1nln
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CRYSTAL STRUCTURE OF HUMAN ADENOVIRUS 2 PROTEINASE WITH ITS 11 AMINO ACID COFACTOR AT 1.6 ANGSTROM RESOLUTION
OverviewOverview
The crystal structure of the human adenovirus proteinase (AVP), a cysteine, proteinase covalently bound to its 11-amino-acid peptide cofactor pVIc, has been solved to 1.6-A resolution with a crystallographic R-factor of, 0.136, R(free)=0.179. The fold of AVP-pVIc is new and the structural basis, for it is described in detail. The polypeptide chain of AVP folds into two, domains. One domain contains a five-strand beta-sheet with two peripheral, alpha-helices; this region represents the hydrophobic core of the protein., A second domain contains the N terminus, several C-terminal alpha-helices, and a small peripheral anti-parallel beta-sheet. The domains interact, through an extended polar interface. pVIc spans the two domains like a, strap, its C-terminal portion forming a sixth strand on the beta-sheet., The active site is in a long, deep groove located between the two domains., Portions are structurally similar to the active site of the prototypical, cysteine proteinase papain, especially some of the Calpha backbone atoms, (r.m.s. deviation of 0.354 A for 12 Calpha atoms). The active-site, nucleophile of AVP, the conserved Cys(122), was shown to have a pK(a) of, 4.5, close to the pK(a) of 3.0 for the nucleophile of papain, suggesting, that a similar ion pair arrangement with His(54) may be present in, AVP-pVIc. The interactions between AVP and pVIc include 24 non-beta-strand, hydrogen bonds, six beta-strand hydrogen bonds and one covalent bond. Of, the 204 amino acid residues in AVP, 33 are conserved among the many, serotypes of adenovirus, and these aid in forming the active site groove, are involved in substrate specificity or interact between secondary, structure elements.
About this StructureAbout this Structure
1NLN is a Single protein structure of sequence from Human adenovirus 2 with ACY as ligand. Active as Adenain, with EC number 3.4.22.39 Full crystallographic information is available from OCA.
ReferenceReference
Crystallographic structure at 1.6-A resolution of the human adenovirus proteinase in a covalent complex with its 11-amino-acid peptide cofactor: insights on a new fold., McGrath WJ, Ding J, Didwania A, Sweet RM, Mangel WF, Biochim Biophys Acta. 2003 May 30;1648(1-2):1-11. PMID:12758141
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