1arg: Difference between revisions

Revision as of 10:37, 2 May 2008

ASPARTATE AMINOTRANSFERASE, PHOSPHO-5'-PYRIDOXYL ASPARTATE COMPLEX

OverviewOverview

The electron distribution in the coenzyme-substrate adduct of aspartate aminotransferase was changed by replacing active-site Arg386 with alanine and introducing a new arginine residue nearby. [Y225R, R386A]Aspartate aminotransferase decarboxylates L-aspartate to L-alanine (kcat = 0.04 s-1), while its transaminase activity towards dicarboxylic amino acids is decreased by three orders of magnitude (kcat = 0.19 s-1). Molecular-dynamics simulations based on the crystal structure of the mutant enzyme suggest that a new hydrogen bond to the imine N atom of the pyridoxal-5'-phosphate- aspartate adduct and an altered electrostatic potential around its beta-carboxylate group underlie the 650,000-fold increase in the ratio of beta-decarboxylase/transaminase activity.

About this StructureAbout this Structure

1ARG is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.

ReferenceReference

Changing the reaction specificity of a pyridoxal-5'-phosphate-dependent enzyme., Graber R, Kasper P, Malashkevich VN, Sandmeier E, Berger P, Gehring H, Jansonius JN, Christen P, Eur J Biochem. 1995 Sep 1;232(2):686-90. PMID:7556224 Page seeded by OCA on Fri May 2 10:37:10 2008

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA

@@ Line 1: / Line 1: @@
 [[Image:1arg.gif|left|200px]]
- {{Structure
+<!--
-|PDB= 1arg |SIZE=350|CAPTION= <scene name='initialview01'>1arg</scene>, resolution 2.2&Aring;
+The line below this paragraph, containing "STRUCTURE_1arg", creates the "Structure Box" on the page.
-|SITE=
+You may change the PDB parameter (which sets the PDB file loaded into the applet)
-|LIGAND= <scene name='pdbligand=PPD:2-[(3-HYDROXY-2-METHYL-5-PHOSPHONOOXYMETHYL-PYRIDIN-4-YLMETHYLENE)-AMINO]-SUCCINIC+ACID'>PPD</scene>
+or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
-|ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Aspartate_transaminase Aspartate transaminase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.6.1.1 2.6.1.1] </span>
+or leave the SCENE parameter empty for the default display.
-|GENE=
+-->
-|DOMAIN=
+{{STRUCTURE_1arg|  PDB=1arg  |  SCENE=  }}
-|RELATEDENTRY=
-|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1arg FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1arg OCA], [http://www.ebi.ac.uk/pdbsum/1arg PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1arg RCSB]</span>
-}}
 '''ASPARTATE AMINOTRANSFERASE, PHOSPHO-5'-PYRIDOXYL ASPARTATE COMPLEX'''
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 [[Category: Jansonius, J N.]]
 [[Category: Malashkevich, V N.]]
-[[Category: transferase (aminotransferase)]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May  2 10:37:10 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 18:46:07 2008''