Structural study of LESV from Arabidopsis thaliana, a new protein involved in starch metabolism

Starch is vital in human nutrition and its unique physical properties are widely used in industrial applications. It accumulates in plants as water-insoluble, semi-crystalline granules. Plants produce and consume their starch over time scales from hours to years. Leaf starch is metabolized in chloroplasts during the diel cycle. The synthesis and degradation rates are under photoperiodic control. Starch is comprised of two glucan polymers (amylose and amylopectin) and its physicochemical properties are defined by their organization within the granule. It has been assumed that the polymers self-organize to form the granule matrix. Recently, however, two conserved but uncharacterized proteins, Early Starvation 1 (ESV1) and Like Early Starvation 1 (LESV), were proposed to organize the polysaccharides within the granules. The mechanism by which this occurs is unknown. We report here preliminary results on the structural organization of LESV from Arabidopsis thaliana.