Genetic Characterization of a Streptococcus mutans LraI Family Operon and Role in Virulence

• DOI: 10.1128/iai.68.8.4441-4451.2000
• Publication Date: 2002-07-27T10:01:19Z
• Authors: Todd Kitten; Cindy L. Munro; Suzanne M. Michalek; Francis L. Macrina
• Keywords: Streptococcus Pyogenes

ABSTRACT Proteins belonging to the LraI (for “lipoprotein receptor antigen”) family function as adhesins in several streptococci, a virulence factor for endocarditis at least one of these species, and potentially metal transporters many bacteria. We have identified characterized chromosomal locus containing gene (designated sloC ) from Streptococcus mutans , an agent dental caries humans. Northern blot analysis indicated that is cotranscribed with three other genes. As operons, sloA sloB genes apparently encode components ATP-binding cassette transport system. The product fourth gene, sloR has homology metal-dependent regulator Corynebacterium diphtheriae DtxR. A potential binding site SloR was upstream sloABCR operon conserved operons streptococci. Potential homologs were unfinished genomic sequences two these, S. pneumoniae pyogenes . Mutagenesis resulted apparent loss expression entire assessed by analysis. mutant indistinguishable its wild-type parent gnotobiotic rat model but significantly less virulent endocarditis. Virulence restored correction mutation not provision trans suggesting requires operon.