Type I beta turns make a new twist in pentapeptide repeat proteins: Crystal structure of Alr5209 from Nostoc sp. PCC 7120 determined at 1.7 angstrom resolution.

ABSTRACT: Pentapeptide repeat proteins (PRPs) are found abundantly in cyanobacteria, numbering in the dozens in some genomes, e.g. in Nostoc sp. PCC 7120. PRPs, comprised of a repeating consensus sequence of five amino acids, adopt a distinctive right-handed quadrilateral β-helical structure, also referred to as a repeat five residue (Rfr) fold, made up of stacks of coils formed by four consecutive pentapeptide repeats. The right-handed quadrilateral β-helical PRP structure is constructed by repeating β turns at each of four corners in a given coil, each causing a 90° change in direction of the polypeptide chain. Until now, all PRP structures have consisted either of type II and IV β turns or exclusively of type II β turns. Here, we report the first structure of a PRP comprised of type I and II β tu

SUBMITTER: Zhang R 

PROVIDER: S-EPMC7337050 | biostudies-literature | 2019 Jul-Sep

REPOSITORIES: biostudies-literature