1e2o

CATALYTIC DOMAIN FROM DIHYDROLIPOAMIDE SUCCINYLTRANSFERASE

spinqualitylabelsall models 1e2o, resolution 3.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1e2o is a 1 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: SO4 Gene: SUCB (Escherichia coli) Activity: Dihydrolipoyllysine-residue succinyltransferase, with EC number 2.3.1.61 Resources: FirstGlance, OCA, RCSB, PDBsum Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed The dihydrolipoamide succinyltransferase (E2o) component of the 2-oxoglutarate dehydrogenase multienzyme complex is composed of 24 subunits arranged with 432 point group symmetry. The catalytic domain (CD) of the E2o component catalyzes the transfer of a succinyl group from the S-succinyldihydrolipoyl moiety to coenzyme A. The crystal structure of the Escherichia coli E2oCD has been solved to 3.0 A resolution using molecular replacement phases derived from the structure of the catalytic domain from the Azotobacter vinelandii dihydrolipoamide acetyltransferase (E2pCD). The refined model of the E. coli E2oCD consists of residues 172 to 404 and has an R-factor of 0.205 (Rfree=0.249) for 9696 reflections between 20.0 and 3.0 A resolution. Although both E2oCD and E2pCD form 24mers, subtle changes in the orientations of two helices in E2oCD increase the stability of the E2oCD 24mer in comparison to the less stable A. vinelandii E2pCD 24mer. Like E2pCD and chloramphenicol acetyltransferase (CAT), the active site of E2oCD is located in the middle of a channel formed at the interface between two 3-fold related subunits. Two of the active-site residues (His375 and Thr323) have a similar orientation to their counterparts in E2pCD and CAT. A third catalytic residue (Asp379) assumes a conformation similar to the corresponding residue in E2pCD (Asn614), but different from its counterpart in CAT (Asp199). Binding of the substrates to E2oCD is proposed to induce a change in the conformation of Asp379, allowing this residue to form a salt bridge with Arg184 that is analogous to that formed between Asp199 and Arg18 in CAT. Computer models of the active site of E2o complexed with dihydrolipoamide and with coenzyme A led to the identification of the probable succinyl-binding pocket. The residues which form this pocket (Ser330, Ser333, and His348) are probably responsible for E2o's substrate specificity. Crystal structure of the truncated cubic core component of the Escherichia coli 2-oxoglutarate dehydrogenase multienzyme complex.,Knapp JE, Mitchell DT, Yazdi MA, Ernst SR, Reed LJ, Hackert ML J Mol Biol. 1998 Jul 24;280(4):655-68. PMID:9677295 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also 2-Oxoglutarate Dehydrogenase

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