Publications

• Assignment of function to histidines 260 and 298 by engineering the E1 component of the Escherichia coli 2-oxoglutarate dehydrogenase complex; substitutions that lead to acceptance of substrates lacking the 5-carboxyl group.

  Shim d.a. J., Nemeria N.S., Balakrishnan A., Patel H., Song J., Wang J., Jordan F., Farinas E.T.

  The first component (E1o) of the Escherichia coli 2-oxoglutarate dehydrogenase complex (OGDHc) was engineered to accept substrates lacking the 5-carboxylate group by subjecting H260 and H298 to saturation mutagenesis. Apparently, H260 is required for substrate recognition, but H298 could be replac ... >> More

  The first component (E1o) of the Escherichia coli 2-oxoglutarate dehydrogenase complex (OGDHc) was engineered to accept substrates lacking the 5-carboxylate group by subjecting H260 and H298 to saturation mutagenesis. Apparently, H260 is required for substrate recognition, but H298 could be replaced with hydrophobic residues of similar molecular volume. To interrogate whether the second component would allow synthesis of acyl-coenzyme A derivatives, hybrid complexes consisting of recombinant components of OGDHc (o) and pyruvate dehydrogenase (p) enzymes were constructed, suggesting that a different component is the "gatekeeper" for specificity for these two multienzyme complexes in bacteria, E1p for pyruvate but E2o for 2-oxoglutarate. << Less

  Biochemistry 50:7705-7709(2011) [PubMed] [EuropePMC]

• Structure-function relationships in the 2-oxo acid dehydrogenase family: substrate-specific signatures and functional predictions for the 2-oxoglutarate dehydrogenase-like proteins.

  Bunik V.I., Degtyarev D.

  Structural relationship within the family of the thiamine diphosphate-dependent 2-oxo acid dehydrogenases was analyzed by combining different methods of sequence alignment with crystallographic and enzymological studies of the family members. For the first time, the sequence similarity of the homo ... >> More

  Structural relationship within the family of the thiamine diphosphate-dependent 2-oxo acid dehydrogenases was analyzed by combining different methods of sequence alignment with crystallographic and enzymological studies of the family members. For the first time, the sequence similarity of the homodimeric 2-oxoglutarate dehydrogenase to heterotetrameric 2-oxo acid dehydrogenases is established. The presented alignment of the catalytic domains of the dehydrogenases of pyruvate, branched-chain 2-oxo acids and 2-oxoglutarate unravels the sequence markers of the substrate specificity and the essential residues of the family members without the 3D structures resolved. Predicted dual substrate specificity of some of the 2-oxo acid dehydrogenases was confirmed experimentally. The results were used to decipher functions of the two hypothetical proteins of animal genomes, OGDHL and DHTKD1, similar to the 2-oxoglutarate dehydrogenase. Conservation of all the essential residues confirmed their catalytic competence. Sequence analysis indicated that OGDHL represents a previously unknown isoform of the 2-oxoglutarate dehydrogenase, whereas DHTKD1 differs from the homologs at the N-terminus and substrate binding pocket. The differences suggest changes in heterologous protein interactions and accommodation of more polar and/or bulkier structural analogs of 2-oxoglutarate, such as 2-oxoadipate, 2-oxo-4-hydroxyglutarate, or products of the carboligase reaction between a 2-oxodicarboxylate and glyoxylate or acetaldehyde. The signatures of the Ca2+-binding sites were found in the Ca2+-activated 2-oxoglutarate dehydrogenase and OGDHL, but not in DHTKD1. Mitochondrial localization was predicted for OGDHL and DHTKD1, with DHTKD1 probably localized also to nuclei. Medical implications of the obtained results are discussed in view of the possible associations of the 2-oxo acid dehydrogenases and DHTKD1 with neurodegeneration and cancer. << Less

  Proteins 71:874-890(2008) [PubMed] [EuropePMC]

• Crystal structure of the E1 component of the Escherichia coli 2-oxoglutarate dehydrogenase multienzyme complex.

  Frank R.A., Price A.J., Northrop F.D., Perham R.N., Luisi B.F.

  The thiamine-dependent E1o component (EC 1.2.4.2) of the 2-oxoglutarate dehydrogenase complex catalyses a rate-limiting step of the tricarboxylic acid cycle (TCA) of aerobically respiring organisms. We describe the crystal structure of Escherichia coli E1o in its apo and holo forms at 2.6 A and 3. ... >> More

  The thiamine-dependent E1o component (EC 1.2.4.2) of the 2-oxoglutarate dehydrogenase complex catalyses a rate-limiting step of the tricarboxylic acid cycle (TCA) of aerobically respiring organisms. We describe the crystal structure of Escherichia coli E1o in its apo and holo forms at 2.6 A and 3.5 A resolution, respectively. The structures reveal the characteristic fold that binds thiamine diphosphate and resemble closely the alpha(2)beta(2) hetero-tetrameric E1 components of other 2-oxo acid dehydrogenase complexes, except that in E1o, the alpha and beta subunits are fused as a single polypeptide. The extended segment that links the alpha-like and beta-like domains forms a pocket occupied by AMP, which is recognised specifically. Also distinctive to E1o are N-terminal extensions to the core fold, and which may mediate interactions with other components of the 2-oxoglutarate dehydrogenase multienzyme complex. The active site pocket contains a group of three histidine residues and one serine that appear to confer substrate specificity and the capacity to accommodate the TCA metabolite oxaloacetate. Oxaloacetate inhibits E1o activity at physiological concentrations, and we suggest that the inhibition may allow coordinated activity within the TCA cycle. We discuss the implications for metabolic control in facultative anaerobes, and for energy homeostasis of the mammalian brain. << Less

  J. Mol. Biol. 368:639-651(2007) [PubMed] [EuropePMC]

• Crystal structure of the truncated cubic core component of the Escherichia coli 2-oxoglutarate dehydrogenase multienzyme complex.

  Knapp J.E., Mitchell D.T., Yazdi M.A., Ernst S.R., Reed L.J., Hackert M.L.

  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-succinyldihydroli ... >> More

  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. << Less

  J. Mol. Biol. 280:655-668(1998) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• Electron cryotomography of the E. coli pyruvate and 2-oxoglutarate dehydrogenase complexes.

  Murphy G.E., Jensen G.J.

  The E. coli pyruvate and 2-oxoglutarate dehydrogenases are two closely related, large complexes that exemplify a growing number of multiprotein "machines" whose domains have been studied extensively and modeled in atomic detail, but whose quaternary structures have remained unclear for lack of an ... >> More

  The E. coli pyruvate and 2-oxoglutarate dehydrogenases are two closely related, large complexes that exemplify a growing number of multiprotein "machines" whose domains have been studied extensively and modeled in atomic detail, but whose quaternary structures have remained unclear for lack of an effective imaging technology. Here, electron cryotomography was used to show that the E1 and E3 subunits of these complexes are flexibly tethered approximately 11 nm away from the E2 core. This result demonstrates unambiguously that electron cryotomography can reveal the relative positions of features as small as 80 kDa in individual complexes, elucidating quaternary structure and conformational flexibility. << Less

  Structure 13:1765-1773(2005) [PubMed] [EuropePMC]

• A trail of research from lipoic acid to alpha-keto acid dehydrogenase complexes.

  Reed L.J.

  J Biol Chem 276:38329-38336(2001) [PubMed] [EuropePMC]

• Three-dimensional solution structure of the E3-binding domain of the dihydrolipoamide succinyltransferase core from the 2-oxoglutarate dehydrogenase multienzyme complex of Escherichia coli.

  Robien M.A., Clore G.M., Omichinski J.G., Perham R.N., Appella E., Sakaguchi K., Gronenborn A.M.

  The three-dimensional solution structure of a 51-residue synthetic peptide comprising the dihydrolipoamide dehydrogenase (E3)-binding domain of the dihydrolipoamide succinyltransferase (E2) core of the 2-oxoglutarate dehydrogenase multienzyme complex of Escherichia coli has been determined by nucl ... >> More

  The three-dimensional solution structure of a 51-residue synthetic peptide comprising the dihydrolipoamide dehydrogenase (E3)-binding domain of the dihydrolipoamide succinyltransferase (E2) core of the 2-oxoglutarate dehydrogenase multienzyme complex of Escherichia coli has been determined by nuclear magnetic resonance spectroscopy and hybrid distance geometry-dynamical simulated annealing calculations. The structure is based on 630 approximate interproton distance and 101 torsion angle (phi, psi, chi 1) restraints. A total of 56 simulated annealing structures were calculated, and the atomic rms distribution about the mean coordinate positions for residues 12-48 of the synthetic peptide is 1.24 A for the backbone atoms, 1.68 A for all atoms, and 1.33 A for all atoms excluding the six side chains which are disordered at chi 1 and the seven which are disordered at chi 2; when the irregular partially disordered loop from residues 31 to 39 is excluded, the rms distribution drops to 0.77 A for the backbone atoms, 1.55 A for all atoms, and 0.89 A for ordered side chains. Although proton resonance assignments for the N-terminal 11 residues and the C-terminal 3 residues were obtained, these two segments of the polypeptide are disordered in solution as evidenced by the absence of nonsequential nuclear Overhauser effects. The solution structure of the E3-binding domain consists of two parallel helices (residues 14-23 and 40-48), a short extended strand (24-26), a five-residue helical-like turn, and an irregular (and more disordered) loop (residues 31-39). This report presents the first structure of an E3-binding domain from a 2-oxo acid dehydrogenase complex.(ABSTRACT TRUNCATED AT 250 WORDS) << Less

  Biochemistry 31:3463-3471(1992) [PubMed] [EuropePMC]