A novel variant of the immunoglobulin fold in surface adhesins of
Staphylococcus aureus: crystal structure of the fibrinogen-binding MSCRAMM,
clumping factor A
Primary Citation of Related Structures:   1N67
PubMed Abstract: 
We report here the crystal structure of the minimal ligand-binding segment of the Staphylococcus aureus MSCRAMM, clumping factor A. This fibrinogen-binding segment contains two similarly folded domains. The fold observed is a new variant of the immunoglobulin motif that we have called DE-variant or the DEv-IgG fold ...
We report here the crystal structure of the minimal ligand-binding segment of the Staphylococcus aureus MSCRAMM, clumping factor A. This fibrinogen-binding segment contains two similarly folded domains. The fold observed is a new variant of the immunoglobulin motif that we have called DE-variant or the DEv-IgG fold. This subgroup includes the ligand-binding domain of the collagen-binding S.aureus MSCRAMM CNA, and many other structures previously classified as jelly rolls. Structure predictions suggest that the four fibrinogen-binding S.aureus MSCRAMMs identified so far would also contain the same DEv-IgG fold. A systematic docking search using the C-terminal region of the fibrinogen gamma-chain as a probe suggested that a hydrophobic pocket formed between the two DEv-IgG domains of the clumping factor as the ligand-binding site. Mutagenic substitution of residues Tyr256, Pro336, Tyr338 and Lys389 in the clumping factor, which are proposed to contact the terminal residues (408)AGDV(411) of the gamma-chain, resulted in proteins with no or markedly reduced affinity for fibrinogen.
Organizational Affiliation: 
Center for Biophysical Sciences and Engineering, School of Optometry, 244 CBSE, 1025 18th Street South, University of Alabama at Birmingham, Birmingham, AL 35294-0005, USA.