Pyruvate dehydrogenase Escherichia coli

Akiyama, S. K, and Hamme.s, G. G., 1981. Elementary. steps in die reaction mechani.sm of die pyruvate dehydrogenase mnltienzyme complex from Escherichia coli Kinetics of flavin reduction. Biochemistry 20 1491-1497. 

The pyruvate dehydrogenase complex from Escherichia coli is considerably more complex than tryptophan synthetase. It has a molecular weight of approximately 4.6 millon and contains three enzymes pyruvate dehydrogenase (Et), dihydrolipoyl transacetylase (E2), and dihydrolipoyl dehydrogenase (E3).82 The overall reaction catalyzed by the complex is... 

The PDH complex contains three enzymes—pyruvate dehydrogenase (EJ, dihydrolipoyl transacetylase (E2), and dihydrolipoyl dehydrogenase (E3)—each present in multiple copies. The number of copies of each enzyme and therefore the size of the complex varies among species. The PDH complex isolated from mammals is about 50 nm in diameter—more than five times the size of an entire ribosome and big enough to be visualized with the electron microscope (Fig. 16-5a). In the bovine enzyme, 60 identical copies of E2 form a pentagonal dodecahedron (the core) with a diameter of about 25 nm (Fig. 16-5b). (The core of the Escherichia coli enzyme contains 24 copies of E2.) E2 is the point of... 

It should be noted that some anaerobic eubacteria (e.g. Escherichia coli, Clostridium acidurici, Chlorobium limicold) possess 2-oxoacid oxidoreductases, either in addition to, or instead of, the dehydrogenase complexes (ref. [37] and references therein). As in the archaebacteria, electrons are transferred to ferredoxin or flavodoxin and the enzymes are small oligomeric proteins. The evolutionary relationships of these enzymes converting pyruvate to acetyl-CoA will be discussed in section 6.2. 

Figure 1 Fermentation pathways of Escherichia coli. Gene symbols ackA, acetate kinase adhE, alcohol dehydrogenase fdh, formate dehydrogenase of FHL complex fhn, nitrate-inducible formate dehydrogenase hyd, hydrogenase 3 of FHL complex IdhA, NAD+-dependent D-(-)-lactate dehydrogenase pfl, pyruvate formate-lyase pta, phosphotransacetylase. FHL, formate hydrogenlyase. Redrawn from reference 29...

Jones, D. D., Horne, H. J., Reche, P. A., and Perham, R. N. 2000. Structural determinants of post-translational modification and catalytic specificity for the lipoyi domains of the pyruvate dehydrogenase multienzyme complex of Escherichia coli. J. Mot. Biol. 295 289-306. 

Arjunan, P, Chandrasekhar, K., Sax, M., et al. (2004) Structural determinants of enzyme binding affinity The El component of pyruvate dehydrogenase from Escherichia coli in complex with the inhibitor thiamin thiazolone diphosphate. Biochemistry 43,2405-2411. 

Deprotonation Rate of the C2-H of Thiamin Diphosphate in the Pyruvate Dehydrogenase Multienzyme Complex from Escherichia coli... 

Akiyama, S. K., Hammes, G. G. (1980), Elementary steps in the reaction mechanism of the pyruvate dehydrogenase multienzyme complex from Escherichia coli kinetics of acetylation and deacetylation, Biochemistry 19, 4208-4213. 

Vitamin Bi is an essential co-factor for several enzymes of carbohydrate metabolism such as transketolase, pyruvate dehydrogenase (PDH), pyruvate decarboxylase and a-ketoglutarate dehydrogenase. To become the active co-factor thiamin pyrophosphate (TPP), thiamin has to be salvaged by thiamin pyrophosphokinase or synthesized de novo. In Escherichia coli and Saccharomyces cerevisiae thiamin biosynthesis proceeds via two branches that have to be combined. In the pyrimidine branch, 4-amino-5-hydroxymethy-2-methylpyrimidine (PIMP) is phosphorylated to 4-amino-2-methyl-5-hydroxymethyl pyrimidine diphosphate (PIMP-PP) by the enzyme HMP/HMP-P kinase (ThiD) however, the step can also be catalyzed by pyridoxine kinase (PdxK), an enzyme also responsible for the activation of vitamin B6 (see below). The second precursor of thiamin biosynthesis, 5-(2-hydroxyethyl)-4-methylthiazole (THZ), is activated by THZ kinase (ThiM) to 4-methyl-5-(2-phosphoethyl)-thiazole (THZ-P), and then the thia-zole and pyrimidine moieties, HMP-PP and THZ-P, are combined to form thiamin phosphate (ThiP) by thiamin phosphate synthase (ThiE). The final step, pyrophosphorylation, yields TPP and is carried out by thiamin pyrophosphorylase (TPK). 

This compound is the product of oxidation of the enamine by any one of the following oxidizing agents on enzymes most commonly by the dithiolane ring of lipoic acid covalently amidated to a lysine side chain in the 2-oxoacid dehydrogenase multienzyme complexes less frequently by FAD in the pyruvate oxidases — these come in two flavors, forming acetate in Escherichia coli and forming acetylphosphate in L. plantarum, finally by NAD. ... 

Y.-H. Park, Protein Interactions in the Pyruvate Dehydrogenase Complex from Escherichia coli. Ph.D. Thesis, Rutgers University Graduate Faculty at Newark, NJ, 2008. 

Escherichia coli Ethanol production Integration of pyruvate dearboxylase and alcohol dehydrogenase 11 from Zymomonas mobilis onto the chromosome of E. coli improve d the stability of the genes over the plasmid-based system, and the ethanol yield was near the maximum theoretical yield on 10% glucose and 8% xylose 48, 98... 

CaJacob. C. A., Frey. P. A., Hainfeld, J. F., Wall, J. S., and Yang, H. (1985). Escherichia coli pyruvate dehydrogenase complex. Particle masses of the complex and component enzymes measured by scanning transmission electron microscopy. Biochemistry 24, 2425-2431. 

Tarmy EM, Kaplan NO. (1968). Kinetics of Escherichia coli B D-lactate dehydrogenase and evidence for pyruvate controlled change in conformation. J Biol Chem, 243, 2587-2596. 

Sanchez AM, Bennett GN, San KY. (2005a). Efficient succinic acid production from glucose through overexpression of pyruvate carboxylase in an Escherichia coli alcohol dehydrogenase and lactate dehydrogenase mutant. Biotechnol Prog, 21, 358-365. 

Thiamine pyrophosphate (18) Affinity chromatography of the pyruvate dehydrogenase complex of wild type Escherichia coli 254... 

Figure 17.7 Aerobic metaboiic pathways involved in SA production in wiid-type Escherichia coli. PEP, phosphoenoipyru-vate OAA, oxaioacetate MAE, maiate FUM, fumarate Suc-CoA, succinyi-CoA a-KG, a-ketoglutarate iCT, isocitrate CiT, citrate GOX, glyoxylate IdhA, iactate dehydrogenase pfIB, pyruvate formateiyase pta, phosphate acetyi-transferase ackA, acetate kinase poxB, pyruvate dehydrogenase ppc, PEP carboxykinase ...

Ohta, K., Beall, D.S., Mejia, J.P, Shanmugam, K.T. et al (1991) Genetic-improvement of Escherichia coli for ethanol-production—chromosomal integration of Zymomonas mohilis genes encoding pyruvate decarboxylase and alcohol dehydrogenase-II. Appl Environ. Microbiol, 57, 893—900. 

Kim, Y, Ingram, L.O., and Shanmugam, K.T. (2008) Dihydrolipoamide dehydrogenase mutation alters the NADH sensitivity of pyruvate dehydrogenase complex of Escherichia coli K-12. J. Bacteriol, 190, 3851—3858. 

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