SclA, a Novel Collagen-Like Surface Protein ofStreptococcus pyogenes

• DOI: 10.1128/iai.68.11.6370-6377.2000
• Publication Date: 2002-07-27T10:01:09Z
• Authors: Magnus Rasmussen; Arvid Edén; Lars Björck
• Keywords: Streptococcus Pyogenes

ABSTRACT Surface proteins of Streptococcus pyogenes are important virulence factors. Here we describe a novel collagen-like surface protein, designated SclA (streptococcal protein). The sclA gene was identified in silico using the Streptococcal Genome Sequencing Project with recently protein GRAB as probe. has signal sequence and cell wall attachment region containing prototypic LPXTGX motif. surface-exposed part contains unique NH 2 -terminal domain 73 amino acids, followed by region. found to be positively regulated Mga, transcriptional activator several S. determinants. A mutant lacking wall-associated constructed effective wild-type bacteria platelet aggregation, survival fresh human blood, adherence pharyngeal cells. all 12 strains that were investigated PCR. Sequence analysis revealed highly conserved. is variable its conserved repeated domains COOH-terminal part. from most have additional proline-rich repeats spacing sequence. hypervariable, but computer predictions indicate common secondary structure, two alpha helices connected loop Immune selection may explain hypervariability region, whereas preserved structure implies this function. These features Mga regulation shared M . Moreover, encoding phylogenetic indicates horizontal transfer contributed evolution sclA.