Emergence of a cell wall protease in the Streptococcus thermophilus population.

ABSTRACT: Streptococcus thermophilus is perceived as a recently emerged food bacterium that evolved from a commensal ancestor by loss and gain of functions. Here, we provide data allowing a better understanding of this evolutionary scheme. A multilocus sequence typing approach that we developed showed that S. thermophilus diverges significantly from its potential ancestors of the salivarius group and displays a low level of allelic variability, confirming its likely recent emergence. An analysis of the origin and dissemination of the prtS gene was carried out within this evolutionary scheme. This gene encodes a protease that allows better growth in milk by facilitating casein breakdown to supply amino acids. The S. thermophilus protease exhibits 95% identity to the animal Streptococcus suis protein

SUBMITTER: Delorme C 

PROVIDER: S-EPMC2805209 | biostudies-literature | 2010 Jan

REPOSITORIES: biostudies-literature