3QB2
The Crystal Structure of Immunity Factor for SPN (IFS)
Summary for 3QB2
Entry DOI | 10.2210/pdb3qb2/pdb |
Related | 3PNT |
Descriptor | Immunity factor for SPN, SULFATE ION (3 entities in total) |
Functional Keywords | glycohydrolase inhibitor, streptococcus pyogenes glycohydrolase toxin, hydrolase inhibitor |
Biological source | Streptococcus pyogenes |
Total number of polymer chains | 4 |
Total formula weight | 90036.76 |
Authors | Smith, C.L.,Ellenberger, T. (deposition date: 2011-01-12, release date: 2011-03-16, Last modification date: 2024-11-06) |
Primary citation | Smith, C.L.,Ghosh, J.,Elam, J.S.,Pinkner, J.S.,Hultgren, S.J.,Caparon, M.G.,Ellenberger, T. Structural Basis of Streptococcus pyogenes Immunity to Its NAD(+) Glycohydrolase Toxin. Structure, 19:192-202, 2011 Cited by PubMed Abstract: The virulence of Gram-positive bacteria is enhanced by toxins like the Streptococcus pyogenes β-NAD(+) glycohydrolase known as SPN. SPN-producing strains of S. pyogenes additionally express the protein immunity factor for SPN (IFS), which forms an inhibitory complex with SPN. We have determined crystal structures of the SPN-IFS complex and IFS alone, revealing that SPN is structurally related to ADP-ribosyl transferases but lacks the canonical binding site for protein substrates. SPN is instead a highly efficient glycohydrolase with the potential to deplete cellular levels of β-NAD(+). The protective effect of IFS involves an extensive interaction with the SPN active site that blocks access to β-NAD(+). The conformation of IFS changes upon binding to SPN, with repacking of an extended C-terminal α helix into a compact shape. IFS is an attractive target for the development of novel bacteriocidal compounds functioning by blocking the bacterium's self-immunity to the SPN toxin. PubMed: 21300288DOI: 10.1016/j.str.2010.12.013 PDB entries with the same primary citation |
Experimental method | X-RAY DIFFRACTION (2.5 Å) |
Structure validation
Download full validation report