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The RcsCB His-Asp Phosphorelay System Is Essential To Overcome Chlorpromazine-Induced Stress in Escherichia coli. Annie Conter, 2002. Induction of a DNA Nickase in the Presence of Its Target Site Stimulates Adaptive Mutation in Escherichia coli. Cesar Rodriguez, 2002.Adaptive mutation to Lac+ in Escherichia coli strain FC40 depends on recombination functions and is enhanced by the expression of conjugal functions . To test the hypothesis that the conjugal function that is important for adaptive mutation is the production of a single-strand nick at the conjugal origin, we supplied an exogenous nicking enzyme, the gene II protein (gIIp) of bacteriophage f1, and placed its target sequence near the lac allele . When both gIIp and its target site were present, adaptive mutation was stimulated three- to fourfold . Like normal adaptive mutations, gIIp-induced mutations were recA+ and ruvC+ dependent and were mainly single-base deletions in runs of iterated bases . In addition, gIIp with its target site could substitute for conjugal functions in adaptive mutation . These results support the hypothesis that nicking at the conjugal origin initiates the recombination that produces adaptive mutations in this strain of E . coli, and they suggest that nicking may be the only conjugal function required for adaptive mutation . P1 Trisaccharide (Gal  1,4Galß1,4GlcNAc) Synthesis by Enzyme Glycosylation Reactions Using Recombinant Escherichia coli.Ziye Liu, 2003.The frequency of Escherichia coli infection has lead to concerns over pathogenic bacteria in our food supply and a demand for therapeutics . Glycolipids on gut cells serve as receptors for the Shiga-like toxin produced by E . coli . Oligosaccharide moiety analogues of these glycolipids can compete with receptors for the toxin, thus acting as antibacterials . An enzymatic synthesis of the P1 trisaccharide (Gal 1,4Galß1,4GlcNAc), one of the oligosaccharide analogues, was assessed in this study . In the proposed synthetic pathway, UDP-glucose was generated from sucrose with an Anabaena sp . sucrose synthase and then converted with an E . coli UDP-glucose 4-epimerase to UDP-galactose . Two molecules of galactose were linked to N-acetylglucosamine subsequently with a Helicobacter pylori ß-l,4-galactosyltransferase and a Neisseria meningitidis
-1,4-galactosyltransferase to produce one molecule of P1 trisaccharide . The four enzymes were coexpressed in a single genetically engineered E . coli strain that was then permeabilized and used to catalyze the enzymatic reaction . P1 trisaccharide was accumulated up to 50 mM (5.4 g in a 200-ml reaction volume), with a 67% yield based on the consumption of N-acetylglucosamine . This study provides an efficient approach for the preparative-scale synthesis of P1 trisaccharide with recombinant bacteria .
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