Publications

• Structural, enzymatic, and genetic studies of beta-ketoacyl-acyl carrier protein synthases I and II of Escherichia coli.

  Garwin J.L., Klages A.L., Cronan J.E. Jr.

  Beta-Ketoacyl-acyl carrier protein synthases I and II of Escherichia coli were purified and characterized. Synthase I was shown to have a molecular weight of 80,000 +/-5,000 and to be composed of two similarly sized subunits. Synthase II had a molecular weight of 85,000 +/-5,000 and also was appar ... >> More

  Beta-Ketoacyl-acyl carrier protein synthases I and II of Escherichia coli were purified and characterized. Synthase I was shown to have a molecular weight of 80,000 +/-5,000 and to be composed of two similarly sized subunits. Synthase II had a molecular weight of 85,000 +/-5,000 and also was apparently homodimeric. Gel electrophoresis of partial proteolytic digests demonstrated that synthases I and II share few if any common peptides. Synthases I and II also were shown to be unrelated by immunological criteria. An improved assay for beta-ketoacyl-acyl carrier protein synthase activity gave kinetic parameters for synthases I and II at both 27 degrees C and 37 degrees C using five long chain acyl-acyl carrier protein substrates. The properties of synthase II are consistent with the proposed role of this enzyme in the modulation of fatty acid synthesis by temperature. fabF mutants of E. coli lack synthase II. The fabF locus was mapped at min 24.5 of the E. coli genetic map and the clockwise map order was found to be pyrC, fabD, fabF, purB. << Less

  J Biol Chem 255:11949-11956(1980) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.

• The 1.3-Angstrom-resolution crystal structure of beta-ketoacyl-acyl carrier protein synthase II from Streptococcus pneumoniae.

  Price A.C., Rock C.O., White S.W.

  The beta-ketoacyl-acyl carrier protein synthases are members of the thiolase superfamily and are key regulators of bacterial fatty acid synthesis. As essential components of the bacterial lipid metabolic pathway, they are an attractive target for antibacterial drug discovery. We have determined th ... >> More

  The beta-ketoacyl-acyl carrier protein synthases are members of the thiolase superfamily and are key regulators of bacterial fatty acid synthesis. As essential components of the bacterial lipid metabolic pathway, they are an attractive target for antibacterial drug discovery. We have determined the 1.3 A resolution crystal structure of the beta-ketoacyl-acyl carrier protein synthase II (FabF) from the pathogenic organism Streptococcus pneumoniae. The protein adopts a duplicated betaalphabetaalphabetaalphabetabeta fold, which is characteristic of the thiolase superfamily. The two-fold pseudosymmetry is broken by the presence of distinct insertions in the two halves of the protein. These insertions have evolved to bind the specific substrates of this particular member of the thiolase superfamily. Docking of the pantetheine moiety of the substrate identifies the loop regions involved in substrate binding and indicates roles for specific, conserved residues in the substrate binding tunnel. The active site triad of this superfamily is present in spFabF as His 303, His 337, and Cys 164. Near the active site is an ion pair, Glu 346 and Lys 332, that is conserved in the condensing enzymes but is unusual in our structure in being stabilized by an Mg(2+) ion which interacts with Glu 346. The active site histidines interact asymmetrically with Lys 332, whose positive charge is closer to His 303, and we propose a specific role for the lysine in polarizing the imidazole ring of this histidine. This asymmetry suggests that the two histidines have unequal roles in catalysis and provides new insights into the catalytic mechanisms of these enzymes. << Less

  J Bacteriol 185:4136-4143(2003) [PubMed] [EuropePMC]

• The putative fabJ gene of Escherichia coli fatty acid synthesis is the fabF gene.

  Magnuson K., Carey M.R., Cronan J.E. Jr.

  Siggaard-Andersen and coworkers (M. Siggaard-Andersen, M. Wissenbach, J. Chuck, I. Svendsen, J. G. Olsen, and P. von Wettstein-Knowles, Proc. Natl. Acad. Sci. USA 91:11027-11031, 1994) recently reported the DNA sequence of a gene encoding a beta-ketoacyl-acyl carrier protein synthase from Escheric ... >> More

  Siggaard-Andersen and coworkers (M. Siggaard-Andersen, M. Wissenbach, J. Chuck, I. Svendsen, J. G. Olsen, and P. von Wettstein-Knowles, Proc. Natl. Acad. Sci. USA 91:11027-11031, 1994) recently reported the DNA sequence of a gene encoding a beta-ketoacyl-acyl carrier protein synthase from Escherichia coli. These workers assigned this gene the designation fabJ and reported that the gene encoded a new beta-ketoacyl-acyl carrier protein synthase. We report that the fabJ gene is the previously reported fabF gene that encodes the known beta-ketoacyl-acyl carrier protein synthase II. << Less

  J. Bacteriol. 177:3593-3595(1995) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• Beta-ketoacyl-acyl carrier protein synthase II of Escherichia coli. Evidence for function in the thermal regulation of fatty acid synthesis.

  Garwin J.L., Klages A.L., Cronan J.E. Jr.

  Cvc-mutants of Escherichia coli are deficient in the synthesis of cis-vaccenic acid and in the temperature control of fatty acid synthesis. In this communication, it is demonstrated that these mutants lack beta-ketoacyl-acyl carrier protein synthase II. The deficiencies in cis-vaccenate synthesis ... >> More

  Cvc-mutants of Escherichia coli are deficient in the synthesis of cis-vaccenic acid and in the temperature control of fatty acid synthesis. In this communication, it is demonstrated that these mutants lack beta-ketoacyl-acyl carrier protein synthase II. The deficiencies in cis-vaccenate synthesis and synthase II are shown to be due to a lesion in the same gene, fabF. Lesions in the fabF gene are found to affect growth only when the strain also carries a lesion in the fabB gene, the structural gene for beta-ketoacyl-acyl carrier protein synthase I. << Less

  J. Biol. Chem. 255:3263-3265(1980) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• Multiple forms of beta-ketoacyl-acyl carrier protein synthetase in Escherichia coli.

  D'Agnolo G., Rosenfeld I.S., Vagelos P.R.

  Two forms of beta-ketoacyl-acyl carrier protein (ACP) synthetase (designated I and II) have been identified in extracts of Escherichia coli. Synthetase I corresponds to the condensing enzyme that was studied earlier (GREENSPAN, M.D., ALBERTS, A.W., and VAGELOS, P.R. (1969) J. Biol. Chem. 244, 6477 ... >> More

  Two forms of beta-ketoacyl-acyl carrier protein (ACP) synthetase (designated I and II) have been identified in extracts of Escherichia coli. Synthetase I corresponds to the condensing enzyme that was studied earlier (GREENSPAN, M.D., ALBERTS, A.W., and VAGELOS, P.R. (1969) J. Biol. Chem. 244, 6477-6485); synthetase II represents a new form of the enzyme. Synthetase II was isolated as a homogeneous protein. It differs from synthetase I in having a higher molecular weight (76,999 versus 66,000), a lower pH optimum (5.5 to 6.1 versus 7.2), and a greater resistance to denaturation by heat. Synthetase II is similar to synthetase I in that both are inactivated by iodoacetamide, and prior incubation of the enzymes with fatty acyl thioesters prevents the inhibitory effect of iodoacetamide. Both also react with a fatty acyl thioester to form an acyl-enzyme intermediate, and the latter reacts with malonyl-ACP to form a beta-ketoacyl thioester. Specificity studies indicated that synthetase II, like synthetase I, has similar affinities with saturated and cis unsaturated fatty acyl thioesters of ACP that are intermediates in the synthesis of saturated and unsaturated fatty acids, respectively. The two synthetases differ only with respect to reactivity with palmitoleyl thioesters: synthetase II has a lower Km and higher Vmax than synthetase I with palmitoleyl-ACP. This finding suggests that synthetase II functions specifically in the elongation of palmitoleyl-ACP to form cis-vaccenyl-ACP. An investigation of synthetases I and II in two classes of unsaturated fatty acid auxotrophs revealed that synthetase I is absent in one class, fabB. Addition of wild type synthetase I to fabB fatty acid synthetase, which synthesizes only saturated fatty acids, permitted this fatty acid synthetase to synthesize unsaturated fatty acids. These experiments indicate that synthetase I plays a critical role in the synthesis of unsaturated fatty acids. << Less

  J Biol Chem 250:5289-5294(1975) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.

• Cloning of the fabF gene in an expression vector and in vitro characterization of recombinant fabF and fabB encoded enzymes from Escherichia coli.

  Edwards P., Nelsen J.S., Metz J.G., Dehesh K.

  Analysis of the beta-ketoacyl-ACP synthase (KAS) encoded by the fabF gene of Escherichia coli has been hampered by a reported instability of the cloned gene. Here we describe biochemical characterization of purified, active protein from the recombinant fabF gene. This enzyme has the properties asc ... >> More

  Analysis of the beta-ketoacyl-ACP synthase (KAS) encoded by the fabF gene of Escherichia coli has been hampered by a reported instability of the cloned gene. Here we describe biochemical characterization of purified, active protein from the recombinant fabF gene. This enzyme has the properties ascribed to KAS II and not those of a putative KAS IV reported to be encoded by fabJ, a genomic clone with DNA sequence identical to that of fabF. We also characterize active protein from a recombinant fabB gene and suggest that this method may have a general utility for analysis of KAS enzymes. << Less

  FEBS Lett. 402:62-66(1997) [PubMed] [EuropePMC]

  This publication is cited by 6 other entries.