Intramolecular isopeptide but not internal thioester bonds confer proteolytic and significant thermal stability to the S. pyogenes pilus adhesin Spy0125.

ABSTRACT: Streptococcus pyogenes and other Gram-positive bacterial pathogens present long macromolecular filaments known as pili on their surface that mediate adhesion and colonization. These pili are covalent polymers, assembled by sortases. Typically, they comprise a putative adhesin at their tip, a backbone subunit present in multiple copies and a basal subunit that is covalently anchored to the peptidoglycan layer of the cell surface. The crystal structures of pilin subunits revealed the presence of unusual covalent linkages in these proteins, including intramolecular isopeptide and internal thioester bonds. The intramolecular isopeptide bonds in backbone pilins are important for protein stability. Here, using both the wild-type protein and a set of mutants, we assessed the proteolytic and therm

SUBMITTER: Walden M 

PROVIDER: S-EPMC4282584 | biostudies-literature | 2014 Mar

REPOSITORIES: biostudies-literature