1o75

Tp47, the 47-Kilodalton Lipoprotein of Treponema pallidum

spinqualitylabelsall models 1o75, resolution 1.95Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1o75 is a 2 chain structure with sequence from Treponema pallidum. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.95Å Ligands: PDX, XE Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function TA47_TREPA This antigen is a pathogen-specific membrane immunogen. Most abundant of the membrane lipoproteins, only found so far in pathogenic treponemes, suggesting that it is an important structural moiety in the cell envelope of virulent treponemal subspecies. Publication Abstract from PubMed Syphilis is a complex sexually transmitted disease caused by the spirochetal bacterium Treponema pallidum. T. pallidum has remained exquisitely sensitive to penicillin, but the mode of action and lethal targets for beta-lactams are still unknown. We previously identified the T. pallidum 47-kDa lipoprotein (Tp47) as a penicillin-binding protein (PBP). Tp47 contains three hypothetical consensus motifs (SVTK, TEN, and KTG) that typically form the active center of other PBPs. Yet, in this study, mutations of key amino acids within these motifs failed to abolish the penicillin binding activity of Tp47. The crystal structure of Tp47 at a resolution of 1.95 A revealed a fold different from any other known PBP; Tp47 is predominantly beta-sheet, in contrast to the alpha/beta-fold common to other PBPs. It comprises four distinct domains: two complex beta-sheet-containing N-terminal domains and two C-terminal domains that adopt immunoglobulin-like folds. The three hypothetical PBP signature motifs do not come together to form a typical PBP active site. Furthermore, Tp47 is unusual in that it displays beta-lactamase activity (k(cat) for penicillin = 271 +/- 6 s(-1)), a feature that hindered attempts to identify the active site in Tp47 by co-crystallization and mass spectrometric techniques. Taken together, Tp47 does not fit the classical structural and mechanistic paradigms for PBPs, and thus Tp47 appears to represent a new class of PBP. Crystal structure of the 47-kDa lipoprotein of Treponema pallidum reveals a novel penicillin-binding protein.,Deka RK, Machius M, Norgard MV, Tomchick DR J Biol Chem. 2002 Nov 1;277(44):41857-64. Epub 2002 Aug 24. PMID:12196546 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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