A structural explanation for the mechanism and specificity of plant branching enzymes I and IIb.

ABSTRACT: Branching enzymes (BEs) are essential in the biosynthesis of starch and glycogen and play critical roles in determining the fine structure of these polymers. The substrates of these BEs are long carbohydrate chains that interact with these enzymes via multiple binding sites on the enzyme's surface. By controlling the branched-chain length distribution, BEs can mediate the physiological properties of starch and glycogen moieties; however, the mechanism and structural determinants of this specificity remain mysterious. In this study, we identify a large dodecaose binding surface on rice BE I (BEI) that reaches from the outside of the active site to the active site of the enzyme. Mutagenesis activity assays confirm the importance of this binding site in enzyme catalysis, from which we conclud

SUBMITTER: Gavgani HN 

PROVIDER: S-EPMC8695356 | biostudies-literature | 2022 Jan

REPOSITORIES: biostudies-literature