1gsq: Difference between revisions
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|PDB= 1gsq |SIZE=350|CAPTION= <scene name='initialview01'>1gsq</scene>, resolution 2.4Å | |PDB= 1gsq |SIZE=350|CAPTION= <scene name='initialview01'>1gsq</scene>, resolution 2.4Å | ||
|SITE= | |SITE= | ||
|LIGAND= <scene name='pdbligand=GDN:GLUTATHIONE S-(2,4 DINITROBENZENE)'>GDN</scene> | |LIGAND= <scene name='pdbligand=GDN:GLUTATHIONE+S-(2,4+DINITROBENZENE)'>GDN</scene> | ||
|ACTIVITY= [http://en.wikipedia.org/wiki/Glutathione_transferase Glutathione transferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.5.1.18 2.5.1.18] | |ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Glutathione_transferase Glutathione transferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.5.1.18 2.5.1.18] </span> | ||
|GENE= CDNA INSERT OF CLONE PGST5 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=6634 Ommastrephes sloani pacificus]) | |GENE= CDNA INSERT OF CLONE PGST5 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=6634 Ommastrephes sloani pacificus]) | ||
|DOMAIN= | |||
|RELATEDENTRY= | |||
|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1gsq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1gsq OCA], [http://www.ebi.ac.uk/pdbsum/1gsq PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1gsq RCSB]</span> | |||
}} | }} | ||
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[[Category: Ji, X.]] | [[Category: Ji, X.]] | ||
[[Category: Rosenvinge, E C.V.]] | [[Category: Rosenvinge, E C.V.]] | ||
[[Category: glutathione transferase]] | [[Category: glutathione transferase]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 20:50:31 2008'' | ||
Revision as of 20:50, 30 March 2008
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| , resolution 2.4Å | |||||||
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| Ligands: | |||||||
| Gene: | CDNA INSERT OF CLONE PGST5 (Ommastrephes sloani pacificus) | ||||||
| Activity: | Glutathione transferase, with EC number 2.5.1.18 | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
THREE-DIMENSIONAL STRUCTURE, CATALYTIC PROPERTIES AND EVOLUTION OF A SIGMA CLASS GLUTATHIONE TRANSFERASE FROM SQUID, A PROGENITOR OF THE LENS-CRYSTALLINS OF CEPHALOPODS
OverviewOverview
The glutathione transferase from squid digestive gland is unique in its very high catalytic activity toward 1-chloro-2,4-dinitrobenzene and in its ancestral relationship to the genes encoding the S-crystallins of the lens of cephalopod eye. The three-dimensional structure of this glutathione transferase in complex with the product 1-(S-glutathionyl)-2,4-dinitrobenzene (GSDNB) has been solved by multiple isomorphous replacement techniques at a resolution of 2.4 A. Like the cytosolic enzymes from vertebrates, the squid protein is a dimer. The structure is similar in overall topology to the vertebrate enzymes but has a dimer interface that is unique when compared to all of the vertebrate and invertebrate structures thus far reported. The active site of the enzyme is very open, a fact that appears to correlate with the high turnover number (800 s-1 at pH 6.5) toward 1-chloro-2,4-dinitrobenzene. Both kcat and kcat/KmCDNB exhibit pH dependencies consistent with a pKa for the thiol of enzyme-bound GSH of 6.3. The enzyme is not very efficient at catalyzing the addition of GSH to enones and epoxides. This particular characteristic appears to be due to the lack of an electrophilic residue at position 106, which is often found in other GSH transferases. The F106Y mutant enzyme is much improved in catalyzing these reactions. Comparisons of the primary structure, gene structure, and three-dimensional structure with class alpha, mu, and pi enzymes support placing the squid protein in a separate enzyme class, sigma. The unique dimer interface suggests that the class sigma enzyme diverged from the ancestral precursor prior to the divergence of the precursor gene for the alpha, mu, and pi classes.
About this StructureAbout this Structure
1GSQ is a Single protein structure of sequence from Ommastrephes sloani pacificus. Full crystallographic information is available from OCA.
ReferenceReference
Three-dimensional structure, catalytic properties, and evolution of a sigma class glutathione transferase from squid, a progenitor of the lens S-crystallins of cephalopods., Ji X, von Rosenvinge EC, Johnson WW, Tomarev SI, Piatigorsky J, Armstrong RN, Gilliland GL, Biochemistry. 1995 Apr 25;34(16):5317-28. PMID:7727393
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