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| [[Image:1oqz.gif|left|200px]]<br /><applet load="1oqz" size="450" color="white" frame="true" align="right" spinBox="true" | | #REDIRECT [[3s8r]] This PDB entry is obsolete and replaced by 3s8r |
| caption="1oqz, resolution 2.50Å" />
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| '''Crystal Structures of Glutaryl 7-Aminocephalosporanic Acid Acylase: Insight into Autoproteolytic Activation'''<br />
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| ==Overview==
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| Glutaryl 7-aminocephalosporanic acid acylase (GCA, EC 3.5.1.11) is a, member of N-terminal nucleophile (Ntn) hydrolases. The native enzyme is an, (alpha beta)(2) heterotetramer originated from an enzymatically inactive, precursor of a single polypeptide. The activation of precursor GCA, consists of primary and secondary autoproteolytic cleavages, generating a, terminal residue with both a nucleophile and a base and releasing a nine, amino acid spacer peptide. We have determined the crystal structures of, the recombinant selenomethionyl native and S170A mutant precursor from, Pseudomonas sp. strain GK16. Precursor activation is likely triggered by, conformational constraints within the spacer peptide, probably inducing a, peptide flip. Autoproteolytic site solvent molecules, which have been, trapped in a hydrophobic environment by the spacer peptide, may play a, role as a general base for nucleophilic attack. The activation results in, building up a catalytic triad composed of Ser170/His192/Glu624. However, the triad is not linked to the usual hydroxyl but the free alpha-amino, group of the N-terminal serine residue of the native GCA. Mutagenesis and, structural data support the notion that the stabilization of a transient, hydroxazolidine ring during autoproteolysis would be critical during the N, --> O acyl shift. The autoproteolytic activation mechanism for GCA is, described.
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| ==About this Structure==
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| 1OQZ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pseudomonas_sp._se83 Pseudomonas sp. se83]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1OQZ OCA].
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| ==Reference==
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| Crystal structures of glutaryl 7-aminocephalosporanic acid acylase: insight into autoproteolytic activation., Kim JK, Yang IS, Rhee S, Dauter Z, Lee YS, Park SS, Kim KH, Biochemistry. 2003 Apr 15;42(14):4084-93. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=12680762 12680762]
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| [[Category: Pseudomonas sp. se83]]
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| [[Category: Single protein]]
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| [[Category: Dauter, Z.]]
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| [[Category: Kim, J.K.]]
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| [[Category: Kim, K.H.]]
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| [[Category: Lee, Y.S.]]
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| [[Category: Park, S.S.]]
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| [[Category: Rhee, S.]]
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| [[Category: Yang, I.S.]]
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| [[Category: ala mutant]]
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| [[Category: glutaryl 7-aminocephalosporanic acid]]
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| [[Category: glutaryl 7-aminocephalosporanic acid acylase]]
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| [[Category: n-terminal nucleophile (ntn) hydrolases]]
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| ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 23:07:03 2007''
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This PDB entry is obsolete and replaced by 3s8r
