Escherichia coli, phosphate transport

Isolated polynucleotide clusters from Rhodococcus opacus which encode four polypeptides possessing the activities of a NHase (a and /3 subunits), an auxiliary protein P15K that activates the NHase, and a cobalt transporter protein were expressed in Escherichia coli DSM 14459 cells [34]. Methionine nitrile was added continuously to a suspension of the transformant cells (5.6% w/v of wet cells) in phosphate buffer (50 mM, pH 7.5) at 20 °C, at a rate where the nitrile concentration did not exceed 15 g L 1 while maintaining the pH constant at 7.5. After 320 min, the nitrile was completely converted into amide, corresponding to a final product concentration of 176 gL1.4-Methylthio-a-hydroxybutyramide is readily hydrolyzed with calcium hydroxide, where the calcium salt of 4-methylthio-a-hydroxybutyric acid (MHA) can be directly used as a nutritional supplement in animal feed as an alternative to methionine or MHA. 

Fann, M. C. and Maloney, P. C. (1998). Functional symmetry of UhpT, the sugar phosphate transporter of Escherichia coli, J. Biol. Chem., 273, 33 735-33 740. 

Auer, M, Kim, M. J., Lemieux, M. J., Villa, A., Song, J., Li, X.-D. and Wang D.-N. (2001). High-yield expression and functional analysis of Escherichia coli glycerol-3-phosphate transporter, Biochemistry, 40, 6628-6635. 

Her research interests originally focused on biological cell membranes, first working on phosphate transport in Escherichia coli and then the plasma membrane proton ATPase in Saccharomyces cerevisiae. While isolating vanadate-resistant mutants in yeast, she became fascinated with work showing that oral administration of vanadium salts alleviated symptoms of diabetes and switched her research focus to that area. She has pursued the insulin-enhancing mechanism of vanadium salts and complexes in cell culture, the STZ-induced diabetic rat, and human type 2 diabetic patients. The National Institutes of Health, the American Heart Association, and the American Diabetes Association have funded the work in her laboratory. Willsky has lectured all around the world and published both research articles and book chapters in this area. 

Surin, B.P., Cox, G.B., Rosenberg, H. (1987). Molecular studies on the phosphate-specific transport system of Escherichia coli. 

Huang Y, Lemieux MJ, Song J, Auer M, Wang DN. Structure 82. and mechanism of the glycerol-3-phosphate transporter from Escherichia coli. Science 2003 301(5633) 616-620. 

Wang DN. Three-dimensional crystallization of the Escherichia 68. coli glycerol-3-phosphate transporter a member of the major facilitator superfamily. Protein Sci. 2003 12 2748-2756. 

Schreurs, W.J. Rosenberg, H. Effect of silver ions on transport and retention of phosphate by Escherichia coli. J. Bacteriol. 1982,152, 7-13. 

Elvin, C.M., Hardy, C.M. and Rosenberg, H. (1 985) P. exchange mediated by the CIpT-dependent sn-glycerol-3-phosphate transport system in Escherichia coli. Journal of Bacteriology 1 51, 1054-1058. 

Schweizer, H., Argast, M. and Boos, W. (1 982) Characteristics of a binding protein-dependent transport system for sn-glycerol-3-phosphate in Escherichia coli that is part of the pho regulon. Journal of Bacteriology 150, 11 54-11 53. 

Weston, L.A. and Kadner, R.J. (1988) Role of uhp genes in expression of the Escherichia coli sugar-phosphate transport system. Journal of Bacteriology 170, 3375-3 383. 

Willsky, C.R. and Malamy, M.H. (1980) Characterization of two genetically separable inorganic phosphate transport systems in Escherichia coli. Journal of Bacteriology 144, 356-365. 

L-Arabinose, in Escherichia coli B/r, is converted by a series of consecutive reactions, catalyzed by at least one L-arabinose-induced transport system or permease and three enzymes into D-xylulose 5-phosphate... 

---