2bfe: Difference between revisions

Revision as of 13:40, 30 October 2007

REACTIVITY MODULATION OF HUMAN BRANCHED-CHAIN ALPHA-KETOACID DEHYDROGENASE BY AN INTERNAL MOLECULAR SWITCH

OverviewOverview

The dehydrogenase/decarboxylase (E1b) component of the 4 MD human, branched-chain alpha-ketoacid dehydrogenase complex (BCKDC) is a thiamin, diphosphate (ThDP)-dependent enzyme. We have determined the crystal, structures of E1b with ThDP bound intermediates after decarboxylation of, alpha-ketoacids. We show that a key tyrosine residue in the E1b active, site functions as a conformational switch to reduce the reactivity of the, ThDP cofactor through interactions with its thiazolium ring. The, intermediates do not assume the often-postulated enamine state, but likely, a carbanion state. The carbanion presumably facilitates the second, E1b-catalyzed reaction, involving the transfer of an acyl moiety from the, intermediate to a lipoic acid prosthetic group in the transacylase (E2b), component ... [(full description)]

About this StructureAbout this Structure

2BFE is a [Protein complex] structure of sequences from [Homo sapiens] with K, MN, CL, TDP, MRD and GOL as [ligands]. Active as [3-methyl-2-oxobutanoate dehydrogenase (2-methylpropanoyl-transferring)], with EC number [1.2.4.4]. Structure known Active Site: AC1. Full crystallographic information is available from [OCA].

ReferenceReference

A versatile conformational switch regulates reactivity in human branched-chain alpha-ketoacid dehydrogenase., Machius M, Wynn RM, Chuang JL, Li J, Kluger R, Yu D, Tomchick DR, Brautigam CA, Chuang DT, Structure. 2006 Feb;14(2):287-98. PMID:16472748

Page seeded by OCA on Tue Oct 30 12:45:33 2007

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

OCA

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 ==About this Structure==
-BFE is a [[http://en.wikipedia.org/wiki/Protein_complex Protein complex]] structure of sequences from [[http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]] with K, MN, CL, TDP, MRD and GOL as [[http://en.wikipedia.org/wiki/ligands ligands]]. Active as [[http://en.wikipedia.org/wiki/ ]], with EC number [[http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.2.4.4 1.2.4.4]]. Full crystallographic information is available from [[http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2BFE OCA]].
+BFE is a [[http://en.wikipedia.org/wiki/Protein_complex Protein complex]] structure of sequences from [[http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]] with K, MN, CL, TDP, MRD and GOL as [[http://en.wikipedia.org/wiki/ligands ligands]]. Active as [[http://en.wikipedia.org/wiki/3-methyl-2-oxobutanoate_dehydrogenase_(2-methylpropanoyl-transferring) 3-methyl-2-oxobutanoate dehydrogenase (2-methylpropanoyl-transferring)]], with EC number [[http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.2.4.4 1.2.4.4]]. Structure known Active Site: AC1. Full crystallographic information is available from [[http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2BFE OCA]].
 ==Reference==
 A versatile conformational switch regulates reactivity in human branched-chain alpha-ketoacid dehydrogenase., Machius M, Wynn RM, Chuang JL, Li J, Kluger R, Yu D, Tomchick DR, Brautigam CA, Chuang DT, Structure. 2006 Feb;14(2):287-98. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=16472748 16472748]
+[[Category: 3-methyl-2-oxobutanoate dehydrogenase (2-methylpropanoyl-transferring)]]
 [[Category: Homo sapiens]]
 [[Category: Protein complex]]
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 [[Category: thiamine diphosphate]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Oct 29 19:42:28 2007''
+''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Oct 30 12:45:33 2007''