Publications

• Acceptor substrate selectivity and kinetic mechanism of Bacillus subtilis TagA.

  Zhang Y.H., Ginsberg C., Yuan Y., Walker S.

  Wall teichoic acids (WTAs) are anionic polymers that coat the cell walls of Gram-positive bacteria. Because they are essential for survival or virulence in many organisms, the enzymes involved in the biosynthesis of WTAs are attractive antibiotic targets. The first committed step in the WTA biosyn ... >> More

  Wall teichoic acids (WTAs) are anionic polymers that coat the cell walls of Gram-positive bacteria. Because they are essential for survival or virulence in many organisms, the enzymes involved in the biosynthesis of WTAs are attractive antibiotic targets. The first committed step in the WTA biosynthetic pathway in Bacillus subtilis is catalyzed by TagA, which transfers N-acetylmannosamine (ManNAc) to the C4 hydroxyl of a membrane-anchored N-acetylglucosaminyl diphospholipid (GlcNAc-pp-undecaprenyl, lipid I) to make ManNAc-beta-(1,4)-GlcNAc-pp-undecaprenyl (lipid II). We have previously shown that TagA utilizes an alternative substrate containing a saturated C(13)H(27) lipid chain. Here we use unnatural substrates and products to establish the lipid preferences of the enzyme and to characterize the kinetic mechanism. We report that TagA is a metal ion-independent glycosyltransferase that follows a steady-state ordered Bi-Bi mechanism in which UDP-ManNAc binds first and UDP is released last. TagA shares homology with a large family of bacterial glycosyltransferases, and the work described here should facilitate structural analysis of the enzyme in complex with its substrates. << Less

  Biochemistry 45:10895-10904(2006) [PubMed] [EuropePMC]

• Partial purification and properties of UDP-N-acetylmannosamine:N-acetylglucosaminyl pyrophosphorylundecaprenol N-acetylmannosaminyltransferase from Bacillus subtilis.

  Murazumi N., Kumita K., Araki Y., Ito E.

  An enzyme which catalyzes the conversion of GlcNAc-PP-undecaprenol into ManNAc(beta 1----4)GlcNAc-PP-undecaprenol, a key lipid intermediate in the de novo synthesis of various teichoic acids, was partially purified from the 20,000 x g supernatant fraction of Bacillus subtilis AHU 1035 cell homogen ... >> More

  An enzyme which catalyzes the conversion of GlcNAc-PP-undecaprenol into ManNAc(beta 1----4)GlcNAc-PP-undecaprenol, a key lipid intermediate in the de novo synthesis of various teichoic acids, was partially purified from the 20,000 x g supernatant fraction of Bacillus subtilis AHU 1035 cell homogenate. By means of ammonium sulfate precipitation, gel chromatography, and ion-exchange chromatography, the enzyme was purified about 70-fold, giving a preparation virtually free from substances obstructive to measurement of the N-acetylmannosaminyltransferase reaction. The enzyme was shown to be specific to UDP-ManNAc. The Km value for UDP-ManNAc was 4.4 microM, and the optimum pH was 7.3. The enzyme required 10 mM MgCl2, 0.3 M KCl, 25% glycerol, and 0.1% Nonidet P-40 to function at full activity. << Less

  J. Biochem. 104:980-984(1988) [PubMed] [EuropePMC]

• In vitro reconstitution of two essential steps in wall teichoic acid biosynthesis.

  Ginsberg C., Zhang Y.H., Yuan Y., Walker S.

  Wall teichoic acids (WTAs) are anionic polymers that decorate the cell walls of many gram-positive bacteria. These structures are essential for survival or virulence in many organisms, which makes the enzymes involved in their biosynthesis attractive targets for the development of new antibacteria ... >> More

  Wall teichoic acids (WTAs) are anionic polymers that decorate the cell walls of many gram-positive bacteria. These structures are essential for survival or virulence in many organisms, which makes the enzymes involved in their biosynthesis attractive targets for the development of new antibacterial agents. We present a strategy to obtain WTA biosynthetic intermediates that involves a combination of chemical and enzymatic transformations. Using these intermediates, we have reconstituted the first two committed steps in the biosynthetic pathway. This work enables the exploration of WTA-synthesizing enzymes as antibiotic targets. << Less

  ACS Chem. Biol. 1:25-28(2006) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• A revised pathway proposed for Staphylococcus aureus wall teichoic acid biosynthesis based on in vitro reconstitution of the intracellular steps.

  Brown S., Zhang Y.H., Walker S.

  Resistance to every family of clinically used antibiotics has emerged, and there is a pressing need to explore unique antibacterial targets. Wall teichoic acids (WTAs) are anionic polymers that coat the cell walls of many Gram-positive bacteria. Because WTAs play an essential role in Staphylococcu ... >> More

  Resistance to every family of clinically used antibiotics has emerged, and there is a pressing need to explore unique antibacterial targets. Wall teichoic acids (WTAs) are anionic polymers that coat the cell walls of many Gram-positive bacteria. Because WTAs play an essential role in Staphylococcus aureus colonization and infection, the enzymes involved in WTA biosynthesis are proposed to be targets for antibiotic development. To facilitate the discovery of WTA inhibitors, we have reconstituted the intracellular steps of S. aureus WTA biosynthesis. We show that two intracellular steps in the biosynthetic pathway are different from what was proposed. The work reported here lays the foundation for the discovery and characterization of inhibitors of WTA biosynthetic enzymes to assess their potential for treating bacterial infections. << Less

  Chem. Biol. 15:12-21(2008) [PubMed] [EuropePMC]

  This publication is cited by 3 other entries.