Background: Late embryogenesis-abundant proteins accumulate under water-deficit and are widely distributed in plants and anhydrobiotic organisms. Results: A common bean group-6 LEA protein shows structural disorder, adopts helicity under water deficit or high molecular crowding, and presents oligomeric forms. Conclusion: PvLEA6 protein adopts different conformations and/or a quaternary structure depending on its environment. Significance: Similar characteristics might be present in different LEA proteins, which could be relevant to their function.

Late Embryogenesis Abundant (LEA) proteins are a broadly distributed group involved in the plant response to water deficit. Most of them are predicted to be intrinsically disordered. By partial dehydration and freeze‐thaw in vitro assays, it was shown that some LEA proteins protect other proteins from the effects of water deficit. Given the presumed unstructured character of LEA proteins, we hypothesized that their flexible nature plays a critical role in their interaction with diverse partners. This structural flexibility might be modulated by the cell water status, promoting conformations needed to interact with specific targets. In this work, we report some of the structural and functional properties of LEA proteins from groups 4 and 6. We showed that proteins in both groups are intrinsically unstructured in solution; however, their intrinsic potential to form secondary structure was exhibited by treatment with a structure inducer, which promoted a significant α‐helix formation. A decrease in water availability and an increase in molecular crowding induced folding in both LEA protein groups but in different level. We also determined the protection efficiency of group 4 LEA proteins and proposed a mechanism for this function.This work was partially supported by CONACyT (132258) and DGAPA‐UNAM (IN208212).