1vz8
From Proteopedia
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==Overview== | ==Overview== | ||
| - | The orf6 gene from the clavulanic acid biosynthesis gene cluster encodes, an OAT (ornithine acetyltransferase). Similar to other OATs the enzyme has, been shown to catalyse the reversible transfer of an acetyl group from, N-acetylornithine to glutamate. OATs are Ntn (N-terminal nucleophile), enzymes, but are distinct from the better-characterized Ntn hydrolase, enzymes as they catalyse acetyl transfer rather than a hydrolysis, reaction. In the present study, we describe the X-ray crystal structure of, the OAT, corresponding to the orf6 gene product, to 2.8 A (1 A=0.1 nm), resolution. The larger domain of the structure consists of an, alphabetabetaalpha sandwich as in the structures of Ntn hydrolase enzymes., However, differences in the connectivity reveal that OATs belong to a, structural | + | The orf6 gene from the clavulanic acid biosynthesis gene cluster encodes, an OAT (ornithine acetyltransferase). Similar to other OATs the enzyme has, been shown to catalyse the reversible transfer of an acetyl group from, N-acetylornithine to glutamate. OATs are Ntn (N-terminal nucleophile), enzymes, but are distinct from the better-characterized Ntn hydrolase, enzymes as they catalyse acetyl transfer rather than a hydrolysis, reaction. In the present study, we describe the X-ray crystal structure of, the OAT, corresponding to the orf6 gene product, to 2.8 A (1 A=0.1 nm), resolution. The larger domain of the structure consists of an, alphabetabetaalpha sandwich as in the structures of Ntn hydrolase enzymes., However, differences in the connectivity reveal that OATs belong to a, structural family different from that of other structurally characterized, Ntn enzymes, with one exception: unexpectedly, the alphabetabetaalpha, sandwich of ORF6 (where ORF stands for open reading frame) displays the, same fold as an DmpA (L-aminopeptidase D-ala-esterase/amidase from, Ochrobactrum anthropi), and so the OATs and DmpA form a new structural, subfamily of Ntn enzymes. The structure reveals an, alpha2beta2-heterotetrameric oligomerization state in which the, intermolecular interface partly defines the active site. Models of the, enzyme-substrate complexes suggest a probable oxyanion stabilization, mechanism as well as providing insight into how the enzyme binds its two, differently charged substrates. |
==About this Structure== | ==About this Structure== | ||
| - | 1VZ8 is a | + | 1VZ8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Streptomyces_clavuligerus Streptomyces clavuligerus] with SO4 as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Glutamate_N-acetyltransferase Glutamate N-acetyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.3.1.35 2.3.1.35] Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1VZ8 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: ornithine acetyltransferase]] | [[Category: ornithine acetyltransferase]] | ||
| - | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 15:19:56 2007'' |
Revision as of 13:14, 5 November 2007
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ORNITHINE ACETYLTRANSFERASE (ORF6 GENE PRODUCT- CLAVULANIC ACID BIOSYNTHESIS) FROM STREPTOMYCES CLAVULIGERUS (SEMET STRUCTURE)
Overview
The orf6 gene from the clavulanic acid biosynthesis gene cluster encodes, an OAT (ornithine acetyltransferase). Similar to other OATs the enzyme has, been shown to catalyse the reversible transfer of an acetyl group from, N-acetylornithine to glutamate. OATs are Ntn (N-terminal nucleophile), enzymes, but are distinct from the better-characterized Ntn hydrolase, enzymes as they catalyse acetyl transfer rather than a hydrolysis, reaction. In the present study, we describe the X-ray crystal structure of, the OAT, corresponding to the orf6 gene product, to 2.8 A (1 A=0.1 nm), resolution. The larger domain of the structure consists of an, alphabetabetaalpha sandwich as in the structures of Ntn hydrolase enzymes., However, differences in the connectivity reveal that OATs belong to a, structural family different from that of other structurally characterized, Ntn enzymes, with one exception: unexpectedly, the alphabetabetaalpha, sandwich of ORF6 (where ORF stands for open reading frame) displays the, same fold as an DmpA (L-aminopeptidase D-ala-esterase/amidase from, Ochrobactrum anthropi), and so the OATs and DmpA form a new structural, subfamily of Ntn enzymes. The structure reveals an, alpha2beta2-heterotetrameric oligomerization state in which the, intermolecular interface partly defines the active site. Models of the, enzyme-substrate complexes suggest a probable oxyanion stabilization, mechanism as well as providing insight into how the enzyme binds its two, differently charged substrates.
About this Structure
1VZ8 is a Single protein structure of sequence from Streptomyces clavuligerus with SO4 as ligand. Active as Glutamate N-acetyltransferase, with EC number 2.3.1.35 Structure known Active Site: AC1. Full crystallographic information is available from OCA.
Reference
X-ray crystal structure of ornithine acetyltransferase from the clavulanic acid biosynthesis gene cluster., Elkins JM, Kershaw NJ, Schofield CJ, Biochem J. 2005 Jan 15;385(Pt 2):565-73. PMID:15352873
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