Abstract

Cassava (Manihot esculenta Crantz) is widely considered as one of the most valuable starch source plants with important food material and new energy production. Starch qua the important effectual caloric ingredient were synthesized mainly through a chain of enzymes, in which the committed-step enzymes granule-bound starch synthase (GBSS) were characterized and analyzed with multifarious bioinformatic tools and serves. The results were showed as following: the molecular structures and physicochemical properties of the Megess genes and encoding proteins were calculated; Megbss protein were localized to the cytosol lacking any transmembrane topological structure; the phylogram analysis suggested that the cassava and some crops producing starch were classified into a large groups according to significant functional association and genetic conservation. The secondary structure of the Megbss protein was mainly composed of α-helixes and random coils, and the tertiary structure were modeled successfully, with some key motifs included.Taken together, these results demonstrate that both of Megbss gene and its encoding protein from cassava have the typical molecular structure and function, and the study will lay theoretical foundation for molecular mechanism and genetic regulation researches of starch biosynthesis.

Keywords: Cassava, starch, granule-bound starch synthase, bioinformatics.