1TF0

Crystal structure of the GA module complexed with human serum albumin

Summary for 1TF0

• Entry DOI: 10.2210/pdb1tf0/pdb
• Related: 1AO6 1PRB
• Descriptor: Serum albumin, Peptostreptococcal albumin-binding protein, DECANOIC ACID, ... (4 entities in total)
• Functional Keywords: protein-protein complex, protein binding
• Biological source: Finegoldia magna; More
• Cellular location: Secreted: P02768; Secreted, cell wall ; Peptidoglycan-anchor : Q51911
• Total number of polymer chains: 2
• Total formula weight: 71966.38

Authors

Lejon, S.,Svensson, S.,Bjorck, L.,Frick, I.-M.,Wikstrom, M. (deposition date: 2004-05-26, release date: 2004-09-07, Last modification date: 2024-10-09)

Primary citation

Lejon, S.,Frick, I.-M.,Bjorck, L.,Wikstrom, M.,Svensson, S.
Crystal structure and biological implications of a bacterial albumin binding module in complex with human serum albumin
J.Biol.Chem., 279:42924-42928, 2004

PubMed Abstract: Many bactericide species express surface proteins that interact with human serum albumin (HSA). Protein PAB from the anaerobic bacterium Finegoldia magna (formerly Peptostreptococcus magnus) represents one of these proteins. Protein PAB contains a domain of 53 amino acid residues known as the GA module. GA homologs are also found in protein G of group C and G streptococci. Here we report the crystal structure of HSA in complex with the GA module of protein PAB. The model of the complex was refined to a resolution of 2.7 A and reveals a novel binding epitope located in domain II of the albumin molecule. The GA module is composed of a left-handed three-helix bundle, and residues from the second helix and the loops surrounding it were found to be involved in HSA binding. Furthermore, the presence of HSA-bound fatty acids seems to influence HSA-GA complex formation. F. magna has a much more restricted host specificity compared with C and G streptococci, which is also reflected in the binding of different animal albumins by proteins PAB and G. The structure of the HSA-GA complex offers a molecular explanation to this unusually clear example of bacterial adaptation.

PubMed: 15269208
DOI: 10.1074/jbc.M406957200

Experimental method

X-RAY DIFFRACTION (2.7 Å)