1c4t: Difference between revisions

[[Image:1c4t.gif|left|200px]]<br /><applet load="1c4t" size="350" color="white" frame="true" align="right" spinBox="true"  

The dihydrolipoamide succinyltransferase (E2o) component of the alpha-ketoglutarate dehydrogenase complex catalyzes the transfer of a succinyl group from the S-succinyldihydrolipoyl moiety to coenzyme A. E2o is normally a 24-mer, but is found as a trimer when E2o is expressed with a C-terminal [His]6 tag. The crystal structure of the trimeric form of the catalytic domain (CD) of the Escherichia coli E2o has been solved to 3.0 A resolution using the Molecular Replacement method. The refined model contains an intact trimer in the asymmetric unit and has an R-factor of 0.257 (Rfree = 0.286) for 18,699 reflections between 10.0 and 3.0 A resolution. The core of tE2oCD (residues 187-396) superimposes onto that of the cubic E2oCD with an RMS difference of 0.4 A for all main-chain atoms. The C-terminal end of tE2oCD (residues 397-404) rotates by an average of 37 degrees compared to cubic E2oCD, disrupting the normal twofold interface. Despite the alteration of quaternary structure, the active site of tE2oCD shows no significant differences from that of the cubic E2oCD, although several side chains in the active site are more ordered in the trimeric form of E2oCD. Analysis of the available sequence data suggests that the majority of E2 components have active sites that resemble that of E. coli E2oCD. The remaining E2 components can be divided into three groups based on active-site sequence similarity. Analysis of the surface properties of both crystal forms of E. coli E2oCD suggests key residues that may be involved in the protein-protein contacts that occur between the catalytic and lipoyl domains of E2o.

1C4T 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=SO4:'>SO4</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Dihydrolipoyllysine-residue_succinyltransferase Dihydrolipoyllysine-residue succinyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.3.1.61 2.3.1.61] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1C4T OCA].  

[[Category: Ernst, S R.]]

[[Category: Hackert, M L.]]

[[Category: Knapp, J E.]]

[[Category: Lawson, J E.]]

[[Category: Reed, L J.]]

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:02:29 2008''