GA module

In molecular biology, the GA module, or protein G-related albumin-binding module, is a protein domain which occurs on the surface of numerous Gram-positive bacterial pathogens. Protein G of group C and G Streptococci interacts with the constant region of IgG and with human serum albumin. The GA module is composed of a left-handed three-helix bundle and is found in a range of bacterial cell surface proteins.^[1][2] GA modules may promote bacterial growth and virulence in mammalian hosts by scavenging albumin-bound nutrients and camouflaging the bacteria. Variations in sequence give rise to differences in structure and function between GA modules in different proteins, which could alter pathogenesis and host specificity due to their varied affinities for different species of albumin.^[3] Proteins containing a GA module include PAB from Peptostreptococcus magnus.^[4]

GA module
solution structure of the albumin binding domain of streptococcal protein g
Identifiers
Symbol	GA
Pfam	PF01468
InterPro	IPR002988
SMART	TBC
PROSITE	PDOC00406
MEROPS	C44
SCOP2	1fkm / SCOPe / SUPFAM
TCDB	4.A.6
CAZy	GT16
Available protein structures: Pfam   structures / ECOD   PDB RCSB PDB; PDBe; PDBj PDBsum structure summary

References

1. Lejon S, Frick IM, Bjorck L, Wikstrom M, Svensson S (October 2004). "Crystal structure and biological implications of a bacterial albumin binding module in complex with human serum albumin". J. Biol. Chem. 279 (41): 42924–8. doi:10.1074/jbc.M406957200. PMID 15269208.
2. Johansson MU, de Chateau M, Wikstrom M, Forsen S, Drakenberg T, Bjorck L (March 1997). "Solution structure of the albumin-binding GA module: a versatile bacterial protein domain". J. Mol. Biol. 266 (5): 859–65. doi:10.1006/jmbi.1996.0856. PMID 9086265.
3. He Y, Rozak DA, Sari N, Chen Y, Bryan P, Orban J (August 2006). "Structure, dynamics, and stability variation in bacterial albumin binding modules: implications for species specificity". Biochemistry. 45 (33): 10102–9. doi:10.1021/bi060409m. PMID 16906768.
4. Johansson MU, de Chateau M, Bjorck L, Forsen S, Drakenberg T, Wikstrom M (October 1995). "The GA module, a mobile albumin-binding bacterial domain, adopts a three-helix-bundle structure". FEBS Lett. 374 (2): 257–61. doi:10.1016/0014-5793(95)01121-T. PMID 7589548. S2CID 33851987.

This article incorporates text from the public domain Pfam and InterPro: IPR002988