An ffh mutant of Streptococcus mutans is viable and able to physiologically adapt to low pH in continuous culture
Date
2004
Authors
Crowley P.J.
Svensater G.
Snoep J.L.
Bleiweis A.S.
Brady L.J.
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Previously, we described in Streptococcus mutans strain NG8 a 5-gene operon (sat) that includes ffh, the bacterial homologue of the eukaryotic signal recognition particle (SRP) protein, SR54. A mutation in ffh resulted in acid sensitivity but not loss of viability. In the present study, chemostat-grown cells of the ffh mutant were shown to possess only 26% and 39% of the parental membrane F-ATPase activity and 55% and 75% of parental glucose- phosphotransferase (PTS) activity when pH-7 and pH-5-grown cells, respectively, were assayed. Two-dimensional-gel electrophoretic analyses revealed significant differences in protein profiles between parent and ffh-mutant strains at both pH 5 and pH 7. It appears that the loss of active SRP (Ffh) function, while not lethal, results in substantial alterations in cellular physiology that includes acid tolerance. © 2004 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.
Description
Keywords
adenosine triphosphatase, glucokinase, signal recognition particle, acid tolerance, acidity, alkalinity, article, bacterial cell, bacterial gene, bacterial growth, bacterial survival, bacterium culture, bacterium mutant, cell viability, chemostat, continuous culture, controlled study, enzyme activity, nonhuman, priority journal, protein function, Streptococcus mutans, two dimensional gel electrophoresis, Acclimatization, Bacterial Proteins, Cell Membrane, Hydrogen-Ion Concentration, Kinetics, Operon, Phosphoenolpyruvate Sugar Phosphotransferase System, Proton-Translocating ATPases, Signal Recognition Particle, Streptococcus mutans, Substrate Specificity, Bacteria (microorganisms), Eukaryota, Streptococcus, Streptococcus mutans
Citation
FEMS Microbiology Letters
234
2
234
2