1hux

From Proteopedia

Revision as of 10:08, 23 March 2008

CRYSTAL STRUCTURE OF THE ACIDAMINOCOCCUS FERMENTANS (R)-2-HYDROXYGLUTARYL-COA DEHYDRATASE COMPONENT A

Overview

Acidaminococcus fermentans degrades glutamate via the hydroxyglutarate pathway, which involves the syn-elimination of water from (R)-2-hydroxyglutaryl-CoA in a key reaction of the pathway. This anaerobic process is catalyzed by 2-hydroxyglutaryl-CoA dehydratase, an enzyme with two components (A and D) that reversibly associate during reaction cycles. Component A (CompA), a homodimeric protein of 2x27 kDa, contains a single, bridging [4Fe-4S] cluster and uses the hydrolysis of ATP to deliver an electron to the dehydratase component (CompD), where the electron is used catalytically. The structure of the extremely oxygen-sensitive CompA protein was solved by X-ray crystallography to 3 A resolution. The protein was found to be a member of the actin fold family, revealing a similar architecture and nucleotide-binding site. The key differences between CompA and other members of the actin fold family are: (i) the presence of a cluster binding segment, the "cluster helix"; (ii) the [4Fe-4S] cluster; and (iii) the location of the homodimer interface, which involves the bridging cluster. Possible reaction mechanisms are discussed in light of the close structural similarity to members of the actin-fold family and the functional similarity to the nitrogenase Fe- protein.

About this Structure

1HUX is a Single protein structure of sequence from Acidaminococcus fermentans. Full crystallographic information is available from OCA.

Reference

Crystal structure of the Acidaminococcus fermentans 2-hydroxyglutaryl-CoA dehydratase component A., Locher KP, Hans M, Yeh AP, Schmid B, Buckel W, Rees DC, J Mol Biol. 2001 Mar 16;307(1):297-308. PMID:11243821

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