Protein Domain : Streptococcal non-M secreted SibA IPR009148

Type	Family
Description	At present, Streptococci are amongst the most medically important bacterial species, causing a variety of diseases across a wide range of age groups.They are non-motile, Gram-positive cocci that are facultative or obligate anaerobes, and occur in pairs or chains. These microbes can be separatedinto groups according to their serological specificity, group A Streptococci (GAS) being amongst the most virulent and showing the most antibioticresistance. To combat the sudden surge of infections caused by GAS, namely Streptococcus pyogenes and Streptococcus pneumoniae, researchers have turned to the wealth of information contained within streptococcal genomes as a source of novel drug and vaccine targets. This, coupled with other techniques, such as microarray analysis and comparative genomics, are providing insights into the variations between clinical strains and avirulent commensal bacteria. Virulence factors, like the well-characterised glucan-binding protein from Streptococcus mutans are useful in assigning function to novel ORFs in new genomes.An example of this approach is the recent discovery of the SibA secreted protein of S. pyogenes, an immunoglobulin binding moiety that is completelydifferent from the classical Ig-binding M protein of other GAS isolates [ ].It shows similarity to other GAS glucan-binding proteins and secreted antigens, suggesting a common ancestor. Deletional studies in vitro showed that it is essential for virulence, and has several homologues in other Gram-positive pathogens.
Short Name	SibA