1ta1: Difference between revisions

Revision as of 16:11, 21 February 2008

H141C mutant of rat liver arginase I

OverviewOverview

Rat liver arginase (arginase I) is potently inactivated by diethyl pyrocarbonate, with a second-order rate constant of 113M(-1)s(-1) for the inactivation process at pH 7.0, 25 degrees C. Partial protection from inactivation is provided by the product of the reaction, l-ornithine, while nearly complete protection is afforded by the inhibitor pair, l-ornithine and borate. The role of H141 has been probed by mutagenesis, chemical modulation, and X-ray diffraction. The hyper-reactivity of H141 towards diethyl pyrocarbonate can be explained by its proximity to E277. A proton shuttling role for H141 is supported by its conformational mobility observed among the known arginase structures. H141 is proposed to serve as an acid/base catalyst, deprotonating the metal-bridging water molecule to generate the metal-bridging hydroxide nucleophile, and by protonating the amino group of the product to facilitate its departure.

About this StructureAbout this Structure

1TA1 is a Single protein structure of sequence from Rattus norvegicus with and as ligands. Active as Arginase, with EC number 3.5.3.1 Full crystallographic information is available from OCA.

ReferenceReference

Probing the role of the hyper-reactive histidine residue of arginase., Colleluori DM, Reczkowski RS, Emig FA, Cama E, Cox JD, Scolnick LR, Compher K, Jude K, Han S, Viola RE, Christianson DW, Ash DE, Arch Biochem Biophys. 2005 Dec 1;444(1):15-26. Epub 2005 Oct 13. PMID:16266687

Page seeded by OCA on Thu Feb 21 15:11:28 2008

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

OCA

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-[[Image:1ta1.gif|left|200px]]<br /><applet load="1ta1" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1ta1.gif|left|200px]]<br /><applet load="1ta1" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1ta1, resolution 2.50&Aring;" />
 '''H141C mutant of rat liver arginase I'''<br />
 ==Overview==
-Rat liver arginase (arginase I) is potently inactivated by diethyl, pyrocarbonate, with a second-order rate constant of 113M(-1)s(-1) for the, inactivation process at pH 7.0, 25 degrees C. Partial protection from, inactivation is provided by the product of the reaction, l-ornithine, while nearly complete protection is afforded by the inhibitor pair, l-ornithine and borate. The role of H141 has been probed by mutagenesis, chemical modulation, and X-ray diffraction. The hyper-reactivity of H141, towards diethyl pyrocarbonate can be explained by its proximity to E277. A, proton shuttling role for H141 is supported by its conformational mobility, observed among the known arginase structures. H141 is proposed to serve as, an acid/base catalyst, deprotonating the metal-bridging water molecule to, generate the metal-bridging hydroxide nucleophile, and by protonating the, amino group of the product to facilitate its departure.
+Rat liver arginase (arginase I) is potently inactivated by diethyl pyrocarbonate, with a second-order rate constant of 113M(-1)s(-1) for the inactivation process at pH 7.0, 25 degrees C. Partial protection from inactivation is provided by the product of the reaction, l-ornithine, while nearly complete protection is afforded by the inhibitor pair, l-ornithine and borate. The role of H141 has been probed by mutagenesis, chemical modulation, and X-ray diffraction. The hyper-reactivity of H141 towards diethyl pyrocarbonate can be explained by its proximity to E277. A proton shuttling role for H141 is supported by its conformational mobility observed among the known arginase structures. H141 is proposed to serve as an acid/base catalyst, deprotonating the metal-bridging water molecule to generate the metal-bridging hydroxide nucleophile, and by protonating the amino group of the product to facilitate its departure.
 ==About this Structure==
-TA1 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus] with MN and GOL as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Arginase Arginase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.3.1 3.5.3.1] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1TA1 OCA].
+TA1 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus] with <scene name='pdbligand=MN:'>MN</scene> and <scene name='pdbligand=GOL:'>GOL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Arginase Arginase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.3.1 3.5.3.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TA1 OCA].
 ==Reference==
@@ Line 14: / Line 14: @@
 [[Category: Rattus norvegicus]]
 [[Category: Single protein]]
-[[Category: Ash, D.E.]]
+[[Category: Ash, D E.]]
 [[Category: Cama, E.]]
-[[Category: Christianson, D.W.]]
+[[Category: Christianson, D W.]]
-[[Category: Cox, J.D.]]
+[[Category: Cox, J D.]]
 [[Category: GOL]]
 [[Category: MN]]
@@ Line 24: / Line 24: @@
 [[Category: h141c mutation]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Wed Nov 21 03:06:41 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:11:28 2008''