1ywm
From Proteopedia
|
Crystal structure of the N-terminal domain of group B Streptococcus alpha C protein
Overview
Group B Streptococcus (GBS) is the leading cause of bacterial pneumonia, sepsis, and meningitis among neonates and an important cause of morbidity, among pregnant women and immunocompromised adults. Invasive diseases due, to GBS are attributed to the ability of the pathogen to translocate across, human epithelial surfaces. The alpha C protein (ACP) has been identified, as an invasin that plays a role in internalization and translocation of, GBS across epithelial cells. The soluble N-terminal domain of ACP (NtACP), blocks the internalization of GBS. We determined the 1.86-A resolution, crystal structure of NtACP comprising residues Ser(52) through Leu(225) of, the full-length ACP. NtACP has two domains, an N-terminal beta-sandwich, and a C-terminal three-helix bundle. Structural and topological alignments, reveal that the beta-sandwich shares structural elements with the type III, fibronectin fold (FnIII), but includes structural elaborations that make, it unique. We have identified a potential integrin-binding motif, consisting of Lys-Thr-Asp(146), Arg(110), and Asp(118). A similar, arrangement of charged residues has been described in other invasins. ACP, shows a heparin binding activity that requires NtACP. We propose a, possible heparin-binding site, including one surface of the three-helix, bundle, and nearby portions of the sandwich and repeat domains. We have, validated this prediction using assays of the heparin binding and, cell-adhesion properties of engineered fragments of ACP. This is the first, crystal structure of a member of the highly conserved Gram-positive, surface alpha-like protein family, and it will enable the internalization, mechanism of GBS to be dissected at the atomic level.
About this Structure
1YWM is a Single protein structure of sequence from Streptococcus agalactiae with DTU and GOL as ligands. Full crystallographic information is available from OCA.
Reference
Crystal structure of the N-terminal domain of the group B streptococcus alpha C protein., Auperin TC, Bolduc GR, Baron MJ, Heroux A, Filman DJ, Madoff LC, Hogle JM, J Biol Chem. 2005 May 6;280(18):18245-52. Epub 2005 Mar 6. PMID:15753100
Page seeded by OCA on Wed Nov 21 07:06:12 2007
