Cloning of genes for bacterial glycosyltransferases. I. Selection of hybrid plasmids carrying genes for two glucosyltransferases.

High-Throughput Screening of a Promoter Library Reveals New Persister Mechanisms in Escherichia Coli

“…Although this broad antibiotic sensitivity suggests that the reduced persister levels in Δ waaG , Δ guaA , and Δ guaB mutants are not antibiotic specific, the mechanisms of action likely differ since the proteins encoded by these genes affect unrelated cellular processes. While WaaG is lipopolysaccharide glucosyltransferase I, a member of glycosyltransferase family enzymes ( 38 ), GuaA (guanine monophosphate synthetase) and GuaB (inosine 5′-monophosphate dehydrogenase) synthesize guanine monophosphate from inosine monophosphate ( 39 , 40 ) and comprise the upstream reactions of the ppGpp biosynthesis pathway ( Fig. 4A ).…”

In Vitro Assembly of the Outer Core of the Lipopolysaccharide from Escherichia coli K-12 and Salmonella typhimurium

“…The apparent K m values for UDP-Glc and Hep 2 -1-deP-KLA are 0.162 ± 0.028 mM and 3.85 ± 1.80 μM, respectively, and the k cat is 0.5 s −1 , similar to the values reported previously when WaaG was characterized in crude extracts. 7,8 The Triton X-100 dependence of the WaaG-catalyzed formation of Glc-Hep 2 -1-deP-KLA was investigated (Figure S2 of the Supporting Information). The activity of WaaG increased as the Triton X-100 concentration was increased from 0 to 0.2%; higher concentrations of detergent were inhibitory.…”

“…No Glc-Hep 2 -1-deP-KLA was formed when other sugar donors, such as UDP-galactose, UDP-glucuronic acid, UDP-galacuronic acid, GDP-mannose, ADP-glucose, and GDP-glucose, were used in place of UDP-Glc (Figure S1A,B of the Supporting Information). The apparent K m values for UDP-Glc and Hep 2 -1-deP-KLA are 0.162 ± 0.028 mM and 3.85 ± 1.80 μM, respectively, and the k cat is 0.5 s –1 , similar to the values reported previously when WaaG was characterized in crude extracts. , …”

“…In all of the E. coli and Salmonella outer core OS, HexI, the first hexose on the main chain, is a glucose residue . WaaG has been identified as the UDP-glucose:(heptosyl) lipopolysaccharide α-1,3-glucosyltransferase in E. coli K-12 and S. typhimurium . , In E. coli K-12, HexII and HexIII are both glucose residues, and in S. typhimurium , HexII is a galactose residue and HexIII is a glucose residue (Figure ). WaaO [UDP-glucose:(glucosyl) lipopolysaccharide α-1,3-galactosyltransferase] from E. coli K-12, WaaI [UDP-galactose:(glucosyl) lipopolysaccharide α-1,3-galactosyltransferase] from S. typhimurium , and WaaJ [UDP-glucose:(galactosyl) lipopolysaccharide α-1,2-glucosyltransferase] are responsible for the transfer of these hexose residues. ,,, …”