4aqo

CRYSTAL STRUCTURE OF THE CALCIUM BOUND PKD-like DOMAIN OF COLLAGENASE G FROM CLOSTRIDIUM HISTOLYTICUM AT 0.99 ANGSTROM RESOLUTION.

spinqualitylabelsall models 4aqo, resolution 0.99Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4aqo is a 1 chain structure with sequence from Hathewaya histolytica. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 0.99Å Ligands: CA Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function COLG_HATHI Clostridial collagenases are among the most efficient degraders of eukaryotic collagen known; saprophytes use collagen as a carbon source while pathogens additionally digest collagen to aid in host colonization. Has both tripeptidylcarboxypeptidase on Gly-X-Y and endopeptidase activities; the endopeptidase cuts within the triple helix region of collagen while tripeptidylcarboxypeptidase successively digests the exposed ends, thus clostridial collagenases can digest large sections of collagen (PubMed:3002446). Active on soluble type I collagen, insoluble collagen, azocoll, soluble PZ-peptide (all collagenase substrates) and gelatin (PubMed:9922257). The full-length protein has collagenase activity, while the in vivo derived C-terminally truncated shorter versions only act on gelatin (PubMed:9922257). In vitro digestion of soluble calf skin collagen fibrils requires both ColG and ColH; ColG forms missing the second collagen-binding domain are also synergistic with ColH, although their overall efficiency is decreased (PubMed:18374061, PubMed:22099748). The activator domain (residues 119-388) and catalytic subdomain (389-670) open and close around substrate using a Gly-rich hinge (387-397), allowing digestion when the protein is closed (PubMed:21947205, PubMed:23703618). Binding of collagen requires Ca(2+) and is inhibited by EGTA; the collagen-binding domain (CBD, S3a plus S3b) specifically recognizes the triple-helical conformation made by 3 collagen protein chains in the triple-helical region (PubMed:11121400). Isolated CBD (S3a plus S3b) binds collagen fibrils and sheets of many tissues (PubMed:11913772). Publication Abstract from PubMed Clostridial collagenases are among the most efficient enzymes to degrade by far the most predominant protein in the biosphere. Here we present crystal structures of the peptidases of three clostridial collagenase isoforms (ColG, ColH and ColT). The comparison of unliganded and liganded structures reveal a quaternary subdomain dynamics. In the unliganded ColH structure this globular dynamics is modulated by an aspartate switch motion that binds to the catalytic zinc. We further identified a calcium binding site in proximity to the catalytic zinc. Both ions are required for full activity, explaining why calcium critically affects the enzymatic activity of clostridial collagenases. Our studies further reveal that loops close to the active site thus serve as characteristic substrate selectivity filter. These elements explain the distinct peptidolytic and collagenolytic activities of these enzymes and provide a rational to engineer collagenases with customized substrate specificity as well as for inhibitor design. Structural basis for activity regulation and substrate preference of clostridial collagenases G, H, and T.,Eckhard U, Schonauer E, Brandstetter H J Biol Chem. 2013 May 23. PMID:23703618 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Collagenase 3D structures

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