Molecular characterization of group A streptococcal (GAS) oligopeptide permease (Opp) and its effect on cysteine protease production

Abstract

Bacterial oligopeptide permeases are membrane-associated complexes of five proteins belonging to the ABC-transporter family, which have been found to be involved in obtaining nutrients, cell-wall metabolism, competence, and adherence to host cells. A lambda library of the strain CS101 group A streptococcal (GAS) genome was used to sequence 10,192 bp containing the five genes oppA to oppF of the GAS opp operon. The deduced amino acid sequences exhibited 50-84% homology to pneumococcal AmiA to AmiF sequences. The operon organization of the five genes was confirmed by transcriptional analysis and an additional shorter oppA transcript was detected. Insertional inactivation was used to create serotype M49 strains which did not express either the oppA gene or the ATPase genes, oppD and oppF. The mutation in oppA confirmed that the additional shorter oppA transcript originated from the opp operon and was probably due to an intra-operon transcription terminator site located downstream of oppA. While growth kinetics, binding of serum proteins, and attachment to eukaryotic cells were unaffected, the oppD/F mutants showed reduced production of the cysteine protease, SpeB, and a change in the pattern of secreted proteins. Thus, the GAS opp operon appears to contribute to both protease production and export/processing of secreted proteins.

Inactivation of Streptococcus pyogenes extracellular cysteine protease significantly decreases mouse lethality of serotype M3 and M49 strains.

“…1). Similarly, insertional mutagenesis of the M49 strain followed the strategy and protocols described previously (32,33). In brief, a fragment of the speB gene corresponding to nucleotide 100 to 1157 of a sequence deposited as GenBank accession number M35110 (2) was amplified from genomic DNA of M49 strain CS101 by PCR and cloned into the E. coli vector pSF152 (34).…”

Identification of Staphylococcus aureus virulence genes in a murine model of bacteraemia using signature‐tagged mutagenesis

“…Oligopeptide transport is important for peptide utilization and the proteolytic system in lactococci (Tynkkynen et al, 1993). In group A streptococci, Opp proteins are involved not only in obtaining nutrients but also in adherence, protease production and processing of secreted proteins (Podbielski et al, 1996).…”

Identification of a novel glycoprotein-binding activity in Streptococcus pyogenes regulated by the mga gene

“…M-protein has a dual role, being the major antiphagocytic factor of S. pyogenes and also an adhesin that binds fibronectin, fibrinogen and albumin, among others (Fischetti et al, 1988 ;Schmidt et al, 1993 ;Gubbe et al, 1997). The ability of S. pyogenes to infect and to persist in varied locations of the human host is in part controlled by the multiple-gene regulator of S. pyogenes, Mga, which controls the expression of the M-protein (emm), M-like proteins (fcrA, enn, sph) and C5a peptidase (scpA) genes (Podbielski et al, 1996a). These genes are located in one regulon where the transcription of the genes downstream of the mga gene is monocistronically regulated.…”

“…These genes are located in one regulon where the transcription of the genes downstream of the mga gene is monocistronically regulated. The genes encoding the opacity factor (sof), secreted inhibitor of the complement cascade (sic) and streptococcal cysteine protease (speB) are also regulated by Mga (Podbielski et al, 1996a).…”