Sas20 is a highly flexible starch-binding protein in the Ruminococcus bromii cell-surface amylosome.

ABSTRACT: Ruminococcus bromii is a keystone species in the human gut that has the rare ability to degrade dietary resistant starch (RS). This bacterium secretes a suite of starch-active proteins that work together within larger complexes called amylosomes that allow R. bromii to bind and degrade RS. Starch adherence system protein 20 (Sas20) is one of the more abundant proteins assembled within amylosomes, but little could be predicted about its molecular features based on amino acid sequence. Here, we performed a structure-function analysis of Sas20 and determined that it features two discrete starch-binding domains separated by a flexible linker. We show that Sas20 domain 1 contains an N-terminal β-sandwich followed by a cluster of α-helices, and the nonreducing end of maltooligosaccharides can be

SUBMITTER: Cerqueira FM 

PROVIDER: S-EPMC9112005 | biostudies-literature | 2022 May

REPOSITORIES: biostudies-literature