This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.

Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.

2byj

From Proteopedia

(Difference between revisions)

Jump to: navigation, search

Revision as of 06:25, 4 April 2018

Ornithine aminotransferase mutant Y85I

Structural highlights

2byj is a 3 chain structure with sequence from Human. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:
Related:	1gbn, 1oat, 2can, 2oat
Activity:	Ornithine aminotransferase, with EC number 2.6.1.13
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Disease

[OAT_HUMAN] Defects in OAT are the cause of hyperornithinemia with gyrate atrophy of choroid and retina (HOGA) [MIM:258870]. HOGA is a slowly progressive blinding autosomal recessive disorder.^[1] ^[2] ^[3] ^[4] ^[5] ^[6]

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

Ornithine aminotransferase and 4-aminobutyrate aminotransferase are related pyridoxal phosphate-dependent enzymes having different substrate specificities. The atomic structures of these enzymes have shown (i) that active site differences are limited to the steric positions occupied by two tyrosine residues in ornithine aminotransferase and (ii) that, uniquely among related, structurally characterized aminotransferases, the conserved arginine that binds the alpha-carboxylate of alpha-amino acids interacts tightly with a glutamate residue. To determine the contribution of these residues to the specificities of the enzymes, we analyzed site-directed mutants of ornithine aminotransferase by rapid reaction kinetics, x-ray crystallography, and 13C NMR spectroscopy. Mutation of one tyrosine (Tyr-85) to isoleucine, as found in aminobutyrate aminotransferase, decreased the rate of the reaction of the enzyme with ornithine 1000-fold and increased that with 4-aminobutyrate 16-fold, indicating that Tyr-85 is a major determinant of specificity toward ornithine. Unexpectedly, the limiting rate of the second half of the reaction, conversion of ketoglutarate to glutamate, was greatly increased, although the kinetics of the reverse reaction were unaffected. A mutant in which the glutamate (Glu-235) that interacts with the conserved arginine was replaced by alanine retained its regiospecificity for the delta-amino group of ornithine, but the glutamate reaction was enhanced 650-fold, whereas only a 5-fold enhancement of the ketoglutarate reaction rate resulted. A model is proposed in which conversion of the enzyme to its pyridoxamine phosphate form disrupts the internal glutamate-arginine interaction, thus enabling ketoglutarate but not glutamate to be a good substrate.

Determinants of substrate specificity in omega-aminotransferases.,Markova M, Peneff C, Hewlins MJ, Schirmer T, John RA J Biol Chem. 2005 Oct 28;280(43):36409-16. Epub 2005 Aug 11. PMID:16096275^[7]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Ramesh V, McClatchey AI, Ramesh N, Benoit LA, Berson EL, Shih VE, Gusella JF. Molecular basis of ornithine aminotransferase deficiency in B-6-responsive and -nonresponsive forms of gyrate atrophy. Proc Natl Acad Sci U S A. 1988 Jun;85(11):3777-80. PMID:3375240
↑ Inana G, Chambers C, Hotta Y, Inouye L, Filpula D, Pulford S, Shiono T. Point mutation affecting processing of the ornithine aminotransferase precursor protein in gyrate atrophy. J Biol Chem. 1989 Oct 15;264(29):17432-6. PMID:2793865
↑ Michaud J, Brody LC, Steel G, Fontaine G, Martin LS, Valle D, Mitchell G. Strand-separating conformational polymorphism analysis: efficacy of detection of point mutations in the human ornithine delta-aminotransferase gene. Genomics. 1992 Jun;13(2):389-94. PMID:1612597
↑ Brody LC, Mitchell GA, Obie C, Michaud J, Steel G, Fontaine G, Robert MF, Sipila I, Kaiser-Kupfer M, Valle D. Ornithine delta-aminotransferase mutations in gyrate atrophy. Allelic heterogeneity and functional consequences. J Biol Chem. 1992 Feb 15;267(5):3302-7. PMID:1737786
↑ Michaud J, Thompson GN, Brody LC, Steel G, Obie C, Fontaine G, Schappert K, Keith CG, Valle D, Mitchell GA. Pyridoxine-responsive gyrate atrophy of the choroid and retina: clinical and biochemical correlates of the mutation A226V. Am J Hum Genet. 1995 Mar;56(3):616-22. PMID:7887415
↑ Kobayashi T, Ogawa H, Kasahara M, Shiozawa Z, Matsuzawa T. A single amino acid substitution within the mature sequence of ornithine aminotransferase obstructs mitochondrial entry of the precursor. Am J Hum Genet. 1995 Aug;57(2):284-91. PMID:7668253
↑ Markova M, Peneff C, Hewlins MJ, Schirmer T, John RA. Determinants of substrate specificity in omega-aminotransferases. J Biol Chem. 2005 Oct 28;280(43):36409-16. Epub 2005 Aug 11. PMID:16096275 doi:10.1074/jbc.M506977200

1 Structural highlights
2 Disease
3 Evolutionary Conservation
4 Publication Abstract from PubMed
5 See Also
6 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/2byj"

@@ Line 1: / Line 1: @@
 ==Ornithine aminotransferase mutant Y85I==
 <StructureSection load='2byj' size='340' side='right' caption='[[2byj]], [[Resolution|resolution]] 3.02&Aring;' scene=''>
@@ Line 6: / Line 7: @@
 <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1gbn|1gbn]], [[1oat|1oat]], [[2can|2can]], [[2oat|2oat]]</td></tr>
 <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Ornithine_aminotransferase Ornithine aminotransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.6.1.13 2.6.1.13] </span></td></tr>
-<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2byj FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2byj OCA], [http://pdbe.org/2byj PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2byj RCSB], [http://www.ebi.ac.uk/pdbsum/2byj PDBsum]</span></td></tr>
+<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2byj FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2byj OCA], [http://pdbe.org/2byj PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2byj RCSB], [http://www.ebi.ac.uk/pdbsum/2byj PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=2byj ProSAT]</span></td></tr>
 </table>
 == Disease ==
@@ Line 14: / Line 15: @@
 Check<jmol>
   <jmolCheckbox>
-    <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/by/2byj_consurf.spt"</scriptWhenChecked>
+    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/by/2byj_consurf.spt"</scriptWhenChecked>
     <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
     <text>to colour the structure by Evolutionary Conservation</text>
@@ Line 46: / Line 47: @@
 [[Category: Mitochondrion]]
 [[Category: Plp-dependent enzyme]]
+[[Category: Polymorphism]]
 [[Category: Pyridoxal phosphate]]
 [[Category: Transferase]]
 [[Category: Transit peptide]]

2byj

From Proteopedia

Revision as of 06:25, 4 April 2018

Ornithine aminotransferase mutant Y85I

Structural highlights

Disease

Evolutionary Conservation

Publication Abstract from PubMed

See Also

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

Views

Personal tools

Navigation

Search

Toolbox