1ahx
From Proteopedia
(New page: 200px<br /><applet load="1ahx" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ahx, resolution 2.0Å" /> '''ASPARTATE AMINOTRANSF...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1ahx.gif|left|200px]]<br /><applet load="1ahx" size=" | + | [[Image:1ahx.gif|left|200px]]<br /><applet load="1ahx" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1ahx, resolution 2.0Å" /> | caption="1ahx, resolution 2.0Å" /> | ||
'''ASPARTATE AMINOTRANSFERASE HEXAMUTANT'''<br /> | '''ASPARTATE AMINOTRANSFERASE HEXAMUTANT'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Mutation of six residues of Escherichia coli aspartate aminotransferase | + | Mutation of six residues of Escherichia coli aspartate aminotransferase results in substantial acquisition of the transamination properties of tyrosine amino-transferase without loss of aspartate transaminase activity. X-ray crystallographic analysis of key inhibitor complexes of the hexamutant reveals the structural basis for this substrate selectivity. It appears that tyrosine aminotransferase achieves nearly equal affinities for a wide range of amino acids by an unusual conformational switch. An active-site arginine residue either shifts its position to electrostatically interact with charged substrates or moves aside to allow access of aromatic ligands. |
==About this Structure== | ==About this Structure== | ||
| - | 1AHX is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with PLP and HCI as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [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] Full crystallographic information is available from [http:// | + | 1AHX is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=PLP:'>PLP</scene> and <scene name='pdbligand=HCI:'>HCI</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [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] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1AHX OCA]. |
==Reference== | ==Reference== | ||
| Line 14: | Line 14: | ||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Jansonius, J | + | [[Category: Jansonius, J N.]] |
| - | [[Category: Malashkevich, V | + | [[Category: Malashkevich, V N.]] |
[[Category: HCI]] | [[Category: HCI]] | ||
[[Category: PLP]] | [[Category: PLP]] | ||
[[Category: transferase (aminotransferase)]] | [[Category: transferase (aminotransferase)]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:44:40 2008'' |
Revision as of 09:44, 21 February 2008
|
ASPARTATE AMINOTRANSFERASE HEXAMUTANT
Overview
Mutation of six residues of Escherichia coli aspartate aminotransferase results in substantial acquisition of the transamination properties of tyrosine amino-transferase without loss of aspartate transaminase activity. X-ray crystallographic analysis of key inhibitor complexes of the hexamutant reveals the structural basis for this substrate selectivity. It appears that tyrosine aminotransferase achieves nearly equal affinities for a wide range of amino acids by an unusual conformational switch. An active-site arginine residue either shifts its position to electrostatically interact with charged substrates or moves aside to allow access of aromatic ligands.
About this Structure
1AHX is a Single protein structure of sequence from Escherichia coli with and as ligands. Active as Aspartate transaminase, with EC number 2.6.1.1 Full crystallographic information is available from OCA.
Reference
Alternating arginine-modulated substrate specificity in an engineered tyrosine aminotransferase., Malashkevich VN, Onuffer JJ, Kirsch JF, Jansonius JN, Nat Struct Biol. 1995 Jul;2(7):548-53. PMID:7664122
Page seeded by OCA on Thu Feb 21 11:44:40 2008
