Autocatalytic intramolecular isopeptide bond formation in gram-positive bacterial pili: a QM/MM simulation.

ABSTRACT: Many gram-positive pathogens possess external pili or fimbriae with which they adhere to host cells during the infection process. Unusual dual intramolecular isopeptide bonds between Asn and Lys side chains within the N-terminal and C-terminal domains of the pilus subunits have been observed initially in the Streptococcus pyogenes pilin subunit Spy0128 and subsequently in GBS52 from Streptococcus agalactiae, in the BcpA major pilin of Bacillus cereus and in the RrgB pilin of Streptococcus pneumoniae, among others. Within each pilin subunit, intramolecular isopeptide bonds serve to stabilize the protein. These bonds provide a means to withstand large external mechanical forces, as well as possibly assisting in supporting a conformation favored for pilin subunit polymerization via sortase tr

SUBMITTER: Hu X 

PROVIDER: S-EPMC3081525 | biostudies-literature | 2011 Jan

REPOSITORIES: biostudies-literature