Streptococcus salivarius Isolates of Varying Acid Tolerance Exhibit F1F0-ATPase Conservation

Caries Res. 2021;55(4):288-291. doi: 10.1159/000516175. Epub 2021 Jun 7.

Abstract

Genes encoding the subunits of the membrane-bound F1F0-ATPase (responsible for exporting protons from the cytoplasm and contributing to acid tolerance) were sequenced for 24 non-mutans streptococci isolated from carious lesions. Isolates, mostly Streptococcus salivarius, displayed a continuum of acid tolerance thresholds ranging from pH 4.55 to 3.39, but amino acid alignments of F1F0-ATPase subunits revealed few non-synonymous substitutions and these were unrelated to acid tolerance. Thus, the F1F0-ATPase is highly-conserved among S. salivarius isolates despite varying acid tolerance thresholds, supporting the contention that acid tolerance is determined by the level of gene/protein expression rather than variation in molecular structure.

Keywords: Amino acid sequence comparison; Dental caries; Proton-translocating ATPase; Streptococcus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acids
  • Adenosine Triphosphatases
  • Dental Caries*
  • Humans
  • Protons
  • Streptococcus mutans
  • Streptococcus salivarius*

Substances

  • Acids
  • Protons
  • Adenosine Triphosphatases