![ORCID Icon]({"type":"image","src":"/templates/jsp/_style2/_tandf/images/orcid.svg"} "ORCID Icon"){kind=small}
http://orcid.org/0000-0001-5129-9741
ABSTRACT
ABSTRACT
Late Embryogenesis Abundant (LEA) proteins comprise a heterogeneous group of proteins that accumulate to high levels in the dry seed and in vegetative plant tissues under water deficit. We recently reported that group 4 LEA proteins from Arabidopsis thaliana, regardless of their structural disorder prevalent in aqueous solution, are able to fold into α-helix when subjected to water deficit and/or macromolecular crowding environments. Interestingly, the ability to gain structure under water limiting conditions is circumscribed to the N-terminal conserved region. This environment- driven conformational plasticity has a functional impact because the conserved N-terminal region is necessary and sufficient to prevent the inactivation and/or aggregation of reporter enzymes, when they are subjected to partial dehydration or freeze-thaw treatments. In this addendum we present a broader analysis of the data and propose that the mechanism by which group 4 LEA proteins exert their chaperone-like activity occurs via a selection of particular LEA structural conformations favored by water deficit environments. In addition, we include further observations regarding the abundance and conservation of histidine residues in LEA proteins of this group, particularly at the C-terminal variable region, supporting the presence of an additional function in the same polypeptides as metal ion sequesters. The structural characteristics of group 4 LEA proteins together with their conceivable multifunctionality, a widespread feature in Intrinsically Disordered Proteins (IDPs), raises the possibility of using this set of proteins as a model to investigate the structure-function relationship of IDPs in plants.
One of the most common responses of plants to abiotic stress, particularly, water limitation, is the accumulation of Late Embryogenesis Abundant (LEA) proteins. LEA proteins are present in dry seeds as well as in vegetative and reproductive tissues of all plant species in response to water deficit.1,2 Most LEA proteins are enriched in hydrophilic and small amino acids, physicochemical properties of ‘hydrophilins’, a broader group of proteins represented in all domains of life. Remarkably, a general characteristic of hydrophilin transcripts is that they accumulate in response to water scarcity.3 LEA proteins are classified in 7 families based on the presence of distinctive sequence motifs conserved within each group.1 Group 4 LEA proteins are characterized by an N-terminal conserved region (about 80 residues long) and a C-terminal region variable in sequence and length. The variability of the C-terminal region further classifies LEA4 proteins in 2 subgroups, 4A and 4B, a feature suggesting functional divergence in this family. Proteins in subgroup 4A consist almost exclusively of the N-terminal conserved region, with a short C-terminal end; whereas, subgroup 4B proteins have a C-terminal variable region of about the same length as the N-terminal conserved region. In Arabidopsis thaliana, there are 3 genes encoding LEA4 proteins: AtLEA4–1 and AtLEA4–2, from subgroup 4A, and AtLEA4–5 from subgroup 4B.4 As in the case of other LEA proteins, group 4 LEA proteins are able to prevent the inactivation of reporter enzymes (e.g. lactate dehydrogenase, LDH) upon partial dehydration and freeze-thaw cycles, ascribing them a chaperone-like activity under conditions imposing water deficit. Because this protective effect occurs at low molar ratios of LEA4:LDH, it was proposed that it requires protein-protein interactions.5,6
Recently, we reported that AtLEA4–2 and AtLEA4–5 are intrinsically disordered proteins (IDPs) when fully hydrated; however, in vitro low osmotic potential and/or macromolecular crowding, conditions prevalent under water deficit environments, are able to induce the formation of α-helical structures in these proteins. Our data demonstrated that the N-terminal conserved region of AtLEA4–5, but not the C-terminal variable region, possesses the physicochemical properties to undergo conformational changes, mostly to α-helix, and that this region is necessary and sufficient for its chaperone-like activity under water deficit conditions, suggesting that the formation of the α-helix plays an essential role in the protection mechanism exerted by group 4 LEA proteins.5 This phenomenon is also observed in other LEA protein families. For example, the distinctive conserved motif that defines group 2 LEA proteins, also known as dehydrins, (known as K-segment) has the potential to gain α-helical conformations, not only by the addition of trifluoroethanol, but also in the presence of lipid vesicles.7-9 Interestingly, there are reports indicating that K-segments are required for the protective function of the group 2 LEA proteins.10,11 The 11-mer motif of group 3 LEA proteins was also shown to adopt α-helical structures under different treatments, and there is evidence indicating that it is sufficient to avoid the inactivation of reporter enzymes.12,13 In contrast, group 6 LEA proteins, that show a lower capacity to modify their structure into α-helix, do not exert an efficient protective activity under partial dehydration.6,14 Similarly, group 1 LEA proteins, defined by a 20-mer specific motif, shown to be fully disordered with low propensity to fold,15 present a rather deficient protective activity when compared with group 2, 3 and 4 LEA proteins, and the deletion of the 20-mer motif does not show any effect on this activity.16
Given the ability of these LEA proteins to gain α-helical conformation, in some cases induced by dehydration or by prevalent conditions under water deficit, such as low water potentials and/or macro-molecular crowding,5,14,17-20 it is possible that the mechanism of recognition and interaction with their targets occurs through ‘conformational selection’.21-23 This mechanism has been proposed for various IDPs, in agreement with their structural plasticity, in which the stabilization of the interaction with their targets occurs by selection of one of their fluctuating conformations, fixed by the contact with their partner protein. This mechanism contrasts with that where the IDP adopts a folded-conformation upon contact with a partner protein, this mode of action is called ‘folding upon binding’.21
The data reported by Cuevas-Velazquez et al. (2016)5 indicate that the helical-enriched conformation of group 4 LEA proteins is not only present in equilibrium with the disordered state in aqueous solution, but that it is the main structure under water-limiting conditions, suggesting that the interaction between LEA4 proteins and LDH occurs through a conformational selection mechanism (Fig. 1). It is worth to consider that it has been predicted that α-helices in LEA4 proteins may have an amphipathic character (Fig. 2), a property that might favor a scenario where the folding of these regions, during water limitation, exposes hydrophobic patches allowing a selective binding to partially unfolded protein clients (Fig. 1). This hypothesis could constitute a novel action mechanism for IDPs with chaperone activity. A different class of disordered chaperones, known as conditionally disordered chaperones, consists of proteins with a globular structure, a condition that circumvents its protective action; however, upon an environmental stress their binding domains unfold to recognize and interact with their client proteins, thus preventing unfavorable conformational changes. In this case, the unfolding of some regions of the protein provides the capacity to interact with multiple client proteins, a basic requirement for any chaperone.24,25 In the case of LEA4 proteins, they might use the hydrophobic side of their putative amphipathic helix as the first contact to recognize their partners, taking advantage of their flexible nature to rapidly release their clients when stress has ceased (Fig. 1). In agreement with this hypothesis, it was recently shown that the hydrophobic residues of the K-segment of dehydrins (group 2 LEA proteins), but not the charged residues, are responsible for the protective activity of this region.26
Published online:
31 July 2017Figure 1. A model for a mechanism of action of group 4 LEA proteins. (A) Under non-stress conditions, proteins (blue spheres) present native conformation and full activity, and the concentration of metal ions (gray circles) is that needed for optimal function. When water becomes limiting for protein activities, in the absence of LEA4 proteins, stress-sensitive proteins modify their native structure losing activity and displaying hydrophobic patches (magenta areas); this condition leads to an increase in the concentration of metal ions, which also causes protein inactivation. If stress conditions persist, protein conformations suffer more extreme changes exposing larger hydrophobic regions resulting in protein aggregation. (B) When LEA4 proteins are present under water deficit, their structural equilibrium moves from disordered conformations toward α-helix, favoring their interaction with client proteins through the hydrophobic regions of their amphipathic helices via a conformational selection mechanism. Because of the presence of putative metal binding His residues, LEA 4 proteins will be able to clasp metal ions and circumvent the detrimental effect of their high concentrations on protein activity. In this way the chaperone-like and metal binding activities of LEA4 proteins contribute to preserve the activity of their client proteins to overcome the adverse effects of water deficit on cell functions.
![]({"type":"image","src":"/na101/home/literatum/publisher/tandf/journals/content/kpsb20/2017/kpsb20.v012.i07/15592324.2017.1343777/20180529/images/medium/kpsb_a_1343777_f0001_oc.gif"})
Figure 1. A model for a mechanism of action of group 4 LEA proteins. (A) Under non-stress conditions, proteins (blue spheres) present native conformation and full activity, and the concentration of metal ions (gray circles) is that needed for optimal function. When water becomes limiting for protein activities, in the absence of LEA4 proteins, stress-sensitive proteins modify their native structure losing activity and displaying hydrophobic patches (magenta areas); this condition leads to an increase in the concentration of metal ions, which also causes protein inactivation. If stress conditions persist, protein conformations suffer more extreme changes exposing larger hydrophobic regions resulting in protein aggregation. (B) When LEA4 proteins are present under water deficit, their structural equilibrium moves from disordered conformations toward α-helix, favoring their interaction with client proteins through the hydrophobic regions of their amphipathic helices via a conformational selection mechanism. Because of the presence of putative metal binding His residues, LEA 4 proteins will be able to clasp metal ions and circumvent the detrimental effect of their high concentrations on protein activity. In this way the chaperone-like and metal binding activities of LEA4 proteins contribute to preserve the activity of their client proteins to overcome the adverse effects of water deficit on cell functions.
Published online:
31 July 2017Figure 2. Prediction of amphipathic properties for Arabidopsis group 4 LEA proteins. This illustration shows helical wheel representations of a region for each of the 3 members of group 4 LEA proteins of Arabidopsis thaliana that it is predicted to have amphipathic physicochemical characteristics, some of which are included at the bottom of each scheme. This analysis was performed using the HeliQuest webserver.34 (http://heliquest.ipmc.cnrs.fr/)
![]({"type":"image","src":"/na101/home/literatum/publisher/tandf/journals/content/kpsb20/2017/kpsb20.v012.i07/15592324.2017.1343777/20180529/images/medium/kpsb_a_1343777_f0002_oc.gif"})
Figure 2. Prediction of amphipathic properties for Arabidopsis group 4 LEA proteins. This illustration shows helical wheel representations of a region for each of the 3 members of group 4 LEA proteins of Arabidopsis thaliana that it is predicted to have amphipathic physicochemical characteristics, some of which are included at the bottom of each scheme. This analysis was performed using the HeliQuest webserver.34 (http://heliquest.ipmc.cnrs.fr/)
Because the N-terminal conserved region of group 4 LEA proteins is responsible for the in vitro chaperone-like activity, then one can infer that the C-terminal variable region is dispensable for their protective activity, raising questions such as why has this C-region been maintained through evolution, and what could be its function. One of the hallmarks of the C-terminal variable region is the bias in its amino acid composition. The C-terminal region shows a low representation of positively charged amino acids such as Arg or Lys and, in contrast to the N-terminal region it is enriched in Gly and His residues (Fig. 3). His residues have been involved in the coordination of metal ions in metal-binding proteins27,28; hence, their abundance in the C-terminal region of AtLEA4–5 protein pointed to the possibility that group 4 LEA proteins are capable of binding metal ions. Accordingly, GmPM1 and GmPM9, 2 group 4 LEA proteins from soybean that also show a high content of His residues, are able to bind Fe3+, Cu2+, Ni2+ and Zn2+ but not Ca2+, Mg2+ or Mn2+.29 Thus, it is likely that the AtLEA4–5 C-terminal region has been maintained through evolution because of its putative ability for binding metal ions. This hypothesis can be extended to the other group 4 LEA proteins given the conservation of some of the His residues throughout the different members (sub-group 4A, Fig. 3). Interestingly, the bias in the distribution of the His residues is more prominent in the members of the subgroup 4B, which have the largest C-terminal region (on average, 15% of all His residues are located at the N-terminal region; while 85% His are found at the C-terminal region, Fig. 3B); whereas, sub-group 4A LEA proteins have a high representation of His at the N-terminal conserved region (on average, 58% His at the N-terminal region; 42% His at the C-terminal region, Fig. 3A). Recently, it has been shown that GmPM1 (fitting group 4B) His-rich C-terminal region binds Cu2+, whereas only low binding was detected for the N-terminal region of this protein, containing just 2 His residues.30 This particular characteristic along with their protective function suggests that group 4 LEA proteins are multifunctional polypeptides. Sub-group 4B proteins have evolved as 2-domain polypeptides, each one with distinctive functions; the N-terminal region possesses a chaperone-like activity, while the C-terminal domain binds metal ions. In the case of sub-group 4A proteins, they may accomplish both roles without the need of physical separation between functional domains. Further experimental evidence is required to support this hypothetical functional model. Interestingly enough, LEA proteins from different families are also able to bind metal ions1,29-33; in some cases, data from in vitro assays indicate that metal binding does not affect their structural conformation in aqueous solution,29,31 yet in the case of GmPM1 it seems to play a role in its homo-oligomerization.30 This metal binding property may not be surprising given that water deficit brings with it an increase in the concentration of different solutes, some of which might become detrimental to plant functions; thus, LEA proteins might also act as metal buffers or detoxifiers, and contribute to redox homeostasis (Fig. 1).
Published online:
31 July 2017Figure 3. Histidine residues distribution in sub-groups A and B of group 4 LEA proteins. This scheme shows the amino acid sequences of different group 4 LEA proteins distributed in sub-groups A and B and it illustrates the differential distribution of His residues (highlighted in red) in the 2 sub-groups of LEA4 protein family showing that in proteins of sub-group A, His residues are spread throughout most of the protein body, whereas in those of sub-group B, His residues are mostly restricted to their C-terminal domain. Also, this image shows the conservation of some of these residues in the proteins of these sub-groups. The Arabidopsis group 4 LEA protein sequences are highlighted in the left column: AtLEA4–1 (green), AtLEA4–2 (light blue) and AtLEA4–5 (yellow). Names in the left column correspond to NCBI access numbers.
![]({"type":"image","src":"/na101/home/literatum/publisher/tandf/journals/content/kpsb20/2017/kpsb20.v012.i07/15592324.2017.1343777/20180529/images/medium/kpsb_a_1343777_f0003_oc.gif"})
Figure 3. Histidine residues distribution in sub-groups A and B of group 4 LEA proteins. This scheme shows the amino acid sequences of different group 4 LEA proteins distributed in sub-groups A and B and it illustrates the differential distribution of His residues (highlighted in red) in the 2 sub-groups of LEA4 protein family showing that in proteins of sub-group A, His residues are spread throughout most of the protein body, whereas in those of sub-group B, His residues are mostly restricted to their C-terminal domain. Also, this image shows the conservation of some of these residues in the proteins of these sub-groups. The Arabidopsis group 4 LEA protein sequences are highlighted in the left column: AtLEA4–1 (green), AtLEA4–2 (light blue) and AtLEA4–5 (yellow). Names in the left column correspond to NCBI access numbers.
In summary, the presence of 2 distinctive regions or domains within group 4 LEA proteins represents an opportunity to investigate the molecular details behind the mechanism of this set of moonlighting proteins. The possibility to differentiate between 2 domains with dissimilar functions and each one with distinctive structural properties, points to group 4 LEA proteins as a suitable and attractive model to study the characteristics and evolution of the structure-function relation of intrinsically disordered proteins in higher plants.
Aknowledgements
We thank David F. Rendón-Luna and Paulette S. Romero-Pérez for critical reading of the manuscript.
Disclosure of potential conflicts of interest
No potential conflicts of interest were disclosed.
Funding
This work was partially supported by CONACyT-Mexico grant 221448 to AAC. CLCV received a CONACyT-Mexico PhD fellowship.
References
- Battaglia M, Olvera-Carrillo Y, Garciarrubio A, Campos F, Covarrubias AA. The enigmatic LEA proteins and other hydrophilins. Plant Physiol 2008; 148(1):6-24; PMID:18772351; https://doi.org/10.1104/pp.108.120725 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Hundertmark M, Hincha DK. LEA (Late Embryogenesis Abundant) proteins and their encoding genes in Arabidopsis thaliana. BMC Genomics 2008; 9:118; PMID:18318901; https://doi.org/10.1186/1471-2164-9-118 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Garay-Arroyo A, Colmenero-Flores JM, Garciarrubio A, Covarrubias AA. Highly hydrophilic proteins in prokaryotes and eukaryotes are common during conditions of water deficit. J Biol Chem 2000; 275(8):5668-74; PMID:10681550; https://doi.org/10.1074/jbc.275.8.5668 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Olvera-Carrillo Y, Campos F, Reyes JL, Garciarrubio A, Covarrubias AA. Functional analysis of the group 4 late embryogenesis abundant proteins reveals their relevance in the adaptive response during water deficit in Arabidopsis. Plant Physiol 2010; 154(1):373-90; PMID:20668063; https://doi.org/10.1104/pp.110.158964 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Cuevas-Velazquez CL, Saab-Rincon, G, Reyes, JL, Covarrubias AA. The unstructured N-terminal region of Arabidopsis group 4 late embryogenesis abundant (LEA) proteins is required for folding and for chaperone-like activity under water deficit. J Biol Chem 2016; 291(20):10893-903; PMID:27006402; https://doi.org/10.1074/jbc.M116.720318 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Reyes JL, Rodrigo MJ, Colmenero-Flores JM, Gil JV, Garay-Arroyo A, Campos F, Salamini F, Bartels D, Covaarrubias AA. Hydrophilins from distant organisms can protect enzymatic activities from water limitation effects in vitro. Plant Cell Environ 2005; 28(6):709-18; https://doi.org/10.1111/j.1365-3040.2005.01317.x [Crossref], [Web of Science ®], [Google Scholar]
- Koag MC, Fenton RD, Wilkens S, Close TJ. The binding of maize DHN1 to lipid vesicles. Gain of structure and lipid specificity. Plant Physiol 2003; 131(1):309-16; PMID:12529538; https://doi.org/10.1104/pp.011171 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Mouillon JM, Gustafsson P, Harryson P. Structural investigation of disordered stress proteins. Comparison of full-length dehydrins with isolated peptides of their conserved segments. Plant Physiol 2006; 141(2):638-50; PMID:16565295; https://doi.org/10.1104/pp.106.079848 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Rahman LN, Chen L, Nazim S, Bamm VV, Yaish MW, Moffatt BA, Dutcher JR, Harauz G. Interactions of intrinsically disordered Thellungiella salsuginea dehydrins TsDHN-1 and TsDHN-2 with membranes - synergistic effects of lipid composition and temperature on secondary structure. Biochem Cell Biol 2010; 88(5):791-807; PMID:20921991; https://doi.org/10.1139/O10-026 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Drira M, Saibi W, Brini F, Gargouri A, Masmoudi K, Hanin M. The K-segments of the wheat dehydrin DHN-5 are essential for the protection of lactate dehydrogenase and beta-glucosidase activities in vitro. Mol Biotech 2013; 54(2):643-50; PMID:23054631; https://doi.org/10.1007/s12033-012-9606-8 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Reyes JL, Campos F, Wei H, Arora R, Yang YI, Karlson DT, Covarrubias AA. Functional dissection of hydrophilins during in vitro freeze protection. Plant Cell Environ 2008; 31(12):1781-90; PMID:18761701; https://doi.org/10.1111/j.1365-3040.2008.01879.x [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Shimizu T, Kanamori Y, Furuki T, Kikawada T, Okuda T, Takahashi T, Mihara H, Sakurai M. Desiccation-induced structuralization and glass formation of group 3 late embryogenesis abundant protein model peptides. Biochemistry 2010; 49:1093-104; PMID:20028138; https://doi.org/10.1021/bi901745f [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Furuki T, Sakurai M. Group 3 LEA protein model peptides protect enzymes against desiccation stress. Biochim Biophys Acta 2016; 1864(9):1237-43; PMID:27131872; https://doi.org/10.1016/j.bbapap.2016.04.012 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Rivera-Najera LY, Saab-Rincon G, Battaglia M, Amero C, Pulido NO, Garcia-Hernandez E, Solórzano RM, Reyes JL, Covarrubias AA. A group 6 late embryogenesis abundant protein from common bean is a disordered protein with extended helical structure and oligomer-forming properties. J Biol Chem 2014; 289(46):31995-2009; PMID:25271167; https://doi.org/10.1074/jbc.M114.583369 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Soulages JL, Kim K, Walters C, Cushman JC. Temperature-induced extended helix/random coil transitions in a group 1 late embryogenesis-abundant protein from soybean. Plant Physiol 2002; 128(3):822-32; PMID:11891239; https://doi.org/10.1104/pp.010521 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Campos F, Cuevas-Velazquez C, Fares MA, Reyes JL, Covarrubias AA. Group 1 LEA proteins, an ancestral plant protein group, are also present in other eukaryotes, and in the archeae and bacteria domains. Mol Genet Genomics 2013; 288(10):503-17; PMID:23861025; https://doi.org/10.1007/s00438-013-0768-2 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Bremer A, Wolff M, Thalhammer A, Hincha DK. Folding of intrinsically disordered plant LEA proteins is driven by glycerol-induced crowding and the presence of membranes. FEBS J 2017; 284(6):919-36; PMID:28109185; https://doi.org/10.1111/febs.14023 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Thalhammer A, Bryant G, Sulpice R, Hincha DK. Disordered cold regulated 15 proteins protect chloroplast membranes during freezing through binding and folding, but do not stabilize chloroplast enzymes in vivo. Plant Physiol 2014; 166(1):190-201; PMID:25096979; https://doi.org/10.1104/pp.114.245399 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Tolleter D, Jaquinod M, Mangavel C, Passirani C, Saulnier P, Manon S, Teyssier E, Payet N, Avelange-Macherel MH, Macherel D. Structure and function of a mitochondrial late embryogenesis abundant protein are revealed by desiccation. Plant Cell 2007; 19(5):1580-9; PMID:17526751; https://doi.org/10.1105/tpc.107.050104 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Shih MD, Hsieh TY, Lin TP, Hsing YIC, Hoekstra FA. Characterization of two soybean (Glycine max L.) LEA IV proteins by circular dichroism and fourier transform infrared spectrometry. Plant Cell Physiol 2010; 51(3):395-407; PMID:20071374; https://doi.org/10.1093/pcp/pcq005 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Arai M, Sugase K, Dyson HJ, Wright PE. Conformational propensities of intrinsically disordered proteins influence the mechanism of binding and folding. Proc Natl Acad Sci U S A 2015; 112:9614-9; PMID:26195786; https://doi.org/10.1073/pnas.1512799112 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Gianni S, Dogan J, Jemth P. Distinguishing induced fit from conformational selection. Biophys Chem 2014; 189:33-9; PMID:24747333; https://doi.org/10.1016/j.bpc.2014.03.003 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Hammes GG, Chang YC, Oas TG. Conformational selection or induced fit: A flux description of reaction mechanism. Proc Natl Acad Sci U S A 2009; 106(33):13737-41; PMID:19666553; https://doi.org/10.1073/pnas.0907195106 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Bardwell JC, Jakob U. Conditional disorder in chaperone action. Trends Biochem Sci 2012; 37:517-25; PMID:23018052; https://doi.org/10.1016/j.tibs.2012.08.006 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Jakob U, Kriwacki R, Uversky VN. Conditionally and transiently disordered proteins: Awakening cryptic disorder to regulate protein function. Chem Rev 2014; 114(13):6779-805; PMID:24502763; https://doi.org/10.1021/cr400459c [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Hara M, Endo T, Kamiya K, Kameyama A. The role of hydrophobic amino acids of K-segments in the cryoprotection of lactate dehydrogenase by dehydrins. J Plant Physiol 2017; 210:18-23; PMID:28040625; https://doi.org/10.1016/j.jplph.2016.12.003 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Dong J, Callahan KL, Borotto NB, Vachet RW. Identifying Zn-bound histidine residues in metalloproteins using hydrogen-deuterium exchange mass spectrometry. Anal Chem 2014; 86(1):766-73; PMID:24313328; https://doi.org/10.1021/ac4032719 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Hara M, Fujinaga M, Kuboi T. Metal binding by citrus dehydrin with histidine-rich domains. J Exp Bot 2005; 56(420):2695-703; PMID:16131509; https://doi.org/10.1093/jxb/eri262 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Liu G, Xu H, Zhang L, Zheng Y. Fe binding properties of two soybean (Glycine max L.) LEA 4 proteins associated with antioxidant activity. Plant Cell Physiol 2011; 52(6):994-1002; PMID:21531760; https://doi.org/10.1093/pcp/pcr052 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Liu G, Liu K, Gao Y, Zheng Y. Involvement of C-terminal histidines in soybean PM1 protein oligomerization and Cu2+ binding. Plant Cell Physiol 2017; 58(6):1018-29; PMID:28387856; https://doi.org/10.1093/pcp/pcx046 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Graether SP, Boddington KF. Disorder and function: A review of the dehydrin protein family. Front Plant Sci 2014; 5:576; PMID:25400646; https://doi.org/10.3389/fpls.2014.00576 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Hara M, Kondo M, Kato T. A KS-type dehydrin and its related domains reduce Cu-promoted radical generation and the histidine residues contribute to the radical-reducing activities. J Exp Bot 2013; 64(6):1615-24; PMID:23382551; https://doi.org/10.1093/jxb/ert016 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Liu Y, Wang L, Xing X, Sun L, Pan J, Kong X, Zhang M, Li D. ZmLEA3, a multifunctional group 3 LEA protein from maize (Zea mays L.), is involved in biotic and abiotic stresses. Plant Cell Physiol 2013; 54(6):944-59; PMID:23543751; https://doi.org/10.1093/pcp/pct047 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]
- Gautier R, Douguet D, Antonny B, Dirn G. HELIQUEST: A web server to screen sequences with specific α-helical properties. Bioinformatics 2008; 24(18):2101-2; PMID:18662927; https://doi.org/10.1093/bioinformatics/btn392 [Crossref], [PubMed], [Web of Science ®], [Google Scholar]