Structural Characterization and Functional Assessment of the Alpha-Expansin Precursor in Oryza sativa

Abstract

Expansins are vital proteins that facilitate cell wall loosening, playing a crucial role in plant growth and development. This study investigates the structural and functional characteristics of the alpha-expansin precursor (GenBank ID: AAL79710.1) in Oryza sativa (Japanese rice). Through bioinformatics analyses, including ProtParam, CELLO, and conserved domain identification, we identified key biochemical properties, such as a molecular weight of approximately 28 kDa, a basic isoelectric point (pI 9.40), and significant levels of alanine and glycine. The CELLO analysis predicted the proteins localization primarily in the extracellular space, consistent with its role in modifying the cell wall. Homology searches revealed high similarity to expansin-A29 proteins in related species, while phylogenetic analysis indicated a close evolutionary relationship among monocots. Structural modeling predicted a well-folded protein, though refinement is necessary to address certain discrepancies highlighted in the QMEANDisCo analysis. Our findings underscore the evolutionary conservation of alpha-expansins and their integral role in plant physiology, particularly in cell wall dynamics and stress responses. This research enhances our understanding of alpha-expansins in rice and lays the groundwork for future studies aimed at manipulating these proteins to improve crop resilience and yield under changing environmental conditions.