Characterization of a glutamate transporter operon, glnQHMP, in Streptococcus mutans and its role in acid tolerance.

ABSTRACT: Glutamate contributes to the acid tolerance response (ATR) of many Gram-negative and Gram-positive bacteria, but its role in the ATR of the oral bacterium Streptococcus mutans is unknown. This study describes the discovery and characterization of a glutamate transporter operon designated glnQHMP (Smu.1519 to Smu.1522) and investigates its potential role in acid tolerance. Deletion of glnQHMP resulted in a 95% reduction in transport of radiolabeled glutamate compared to the wild-type UA159 strain. The addition of glutamate to metabolizing UA159 cells resulted in an increased production of acidic end products, whereas the glnQHMP mutant produced less lactic acid than UA159, suggesting a link between glutamate metabolism and acid production and possible acid tolerance. To investigate this pos

SUBMITTER: Krastel K 

PROVIDER: S-EPMC2812961 | biostudies-literature | 2010 Feb

REPOSITORIES: biostudies-literature