1zlh
From Proteopedia
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Crystal structure of the tick carboxypeptidase inhibitor in complex with bovine carboxypeptidase A
Overview
The tick carboxypeptidase inhibitor (TCI) is a proteinaceous inhibitor of metallo-carboxypeptidases present in the blood-sucking tick Rhipicephalus bursa. The three-dimensional crystal structures of recombinant TCI bound to bovine carboxypeptidase A and to human carboxypeptidase B have been determined and refined at 1.7 A and at 2.0 A resolution, respectively. TCI consists of two domains that are structurally similar despite the low degree of sequence homology. The domains, each consisting of a short alpha-helix followed by a small twisted antiparallel beta-sheet, show a high level of structural homology to proteins of the beta-defensin-fold family. TCI anchors to the surface of mammalian carboxypeptidases in a double-headed manner not previously seen for carboxypeptidase inhibitors: the last three carboxy-terminal amino acid residues interact with the active site of the enzyme in a way that mimics substrate binding, and the N-terminal domain binds to an exosite distinct from the active-site groove. The structures of these complexes should prove valuable in the applications of TCI as a thrombolytic drug and as a basis for the design of novel bivalent carboxypeptidase inhibitors.
About this Structure
1ZLH is a Protein complex structure of sequences from Bos taurus and Rhipicephalus bursa with as ligand. Active as Carboxypeptidase A, with EC number 3.4.17.1 Full crystallographic information is available from OCA.
Reference
The three-dimensional structures of tick carboxypeptidase inhibitor in complex with A/B carboxypeptidases reveal a novel double-headed binding mode., Arolas JL, Popowicz GM, Lorenzo J, Sommerhoff CP, Huber R, Aviles FX, Holak TA, J Mol Biol. 2005 Jul 15;350(3):489-98. PMID:15961103
Page seeded by OCA on Thu Feb 21 16:16:43 2008
Categories: Bos taurus | Carboxypeptidase A | Protein complex | Rhipicephalus bursa | Arolas, J L. | Aviles, F X. | Holak, T A. | Huber, R. | Lorenzo, J. | Popowicz, G M. | Sommerhoff, C P. | ZN | Beta-defensin fold (tci) | Eight-stranded twisted beta-sheet surrounded by eight alpha-helices (cpa) | Inhibitor-metallocarboxypeptidase complex