Analysis of polymorphic residues reveals distinct enzymatic and cytotoxic activities of the Streptococcus pyogenes NAD+ glycohydrolase.

ABSTRACT: The Streptococcus pyogenes NAD(+) glycohydrolase (SPN) is secreted from the bacterial cell and translocated into the host cell cytosol where it contributes to cell death. Recent studies suggest that SPN is evolving and has diverged into NAD(+) glycohydrolase-inactive variants that correlate with tissue tropism. However, the role of SPN in both cytotoxicity and niche selection are unknown. To gain insight into the forces driving the adaptation of SPN, a detailed comparison of representative glycohydrolase activity-proficient and -deficient variants was conducted. Of a total 454 amino acids, the activity-deficient variants differed at only nine highly conserved positions. Exchanging residues between variants revealed that no one single residue could account for the inability of the deficient

SUBMITTER: Chandrasekaran S 

PROVIDER: S-EPMC3707703 | biostudies-literature | 2013 Jul

REPOSITORIES: biostudies-literature