scholarly journals The Phosphoenopyruvate-Dependent Carbohydrate: Phosphotransferase System Enzymes II as Chemoreceptors in Chemotaxis of Escherichia coli K12

1981 ◽  
Vol 184 (3) ◽  
pp. 570-570
Author(s):  
J. Lengeler ◽  
A.-M. Auburger ◽  
R. Mayer ◽  
A. Pecher
Keyword(s):  
Escherichia Coli ◽  
Phosphotransferase System ◽  
Escherichia Coli K12

scholarly journals Transport of galactose, glucose and their molecular analogues by Escherichia coli K12

1977 ◽  
Vol 162 (2) ◽  
pp. 309-320 ◽  
Author(s):  
P J F Henderson ◽  
R A Giddens ◽  
M C Jones-Mortimer
Keyword(s):  
Escherichia Coli ◽  
Transport System ◽  
Proton Transport ◽  
Regulatory Mechanism ◽  
Transport Systems ◽  
British Library ◽  
Transport Activity ◽  
Phosphotransferase System ◽  
Escherichia Coli K12 ◽  
Specific Transport System

1. Strains of Escherichia coli K12 were made that are unable to assimilate glucose by the phosphotransferase system, since they lack the glucose-specific components specified by the genes ptsG and ptsM. 2. Derivative organisms lacking the methyl galactoside or galactose-specific transport system were examined for their ability to transport galactose, d-fucose, methyl beta-D-galactoside, glucose, 2-deoxy-D-glucose and methyl alpha-D-glucoside. 3. Galactose, glucose and to a lesser extent fucose are substrates for both transport systems. 4. 2-Deoxyglucose is transported on the galactose-specific but not the methyl galactoside system. 5. The ability of sugars to elicit anaerobic proton transport is associated with the galactose-specific, but not with the methyl galactoside transport activity. Hence a chemiosmotic mechanism of energization is likely to apply to the former but not to the latter. Alternatively the methyl galactoside system may be switched off under certain conditions, which would indicate a novel regulatory mechanism. 6. Details of the procedure for the derivation of strains may be obtained from the authors, and have been deposited as Supplementary Publication SUP 50074 (8 pages at the) British Library Lending Division, Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1977), 161,1.

A novel mutation FruS, altering synthesis of components of the phosphoenolpyruvate: fructose phosphotransferase system in Escherichia coli K12

1992 ◽  
Vol 232 (3) ◽  
pp. 394-398 ◽  
Author(s):  
Tatyana N. Bolshakova ◽  
Marina L. Molchanova ◽  
Raisa S. Erlagaeva ◽  
Yuri A. Grigorenko ◽  
Vladimir N. Gershanovitch
Keyword(s):  
Escherichia Coli ◽  
Novel Mutation ◽  
Phosphotransferase System ◽  
Escherichia Coli K12

scholarly journals Biochemical Genetics of the Cryptic Gene System for Cellobiose Utilization in Escherichia coli K12

Genetics ◽  
1987 ◽  
Vol 115 (3) ◽  
pp. 419-429
Author(s):  
Maja Kricker ◽  
Barry G Hall
Keyword(s):  
Escherichia Coli ◽  
Microbial Evolution ◽  
Transport Protein ◽  
Wild Type ◽  
Phosphotransferase System ◽  
E Coli ◽  
Escherichia Coli K12 ◽  
Biochemical Assays ◽  
In The Wild

ABSTRACT The cellobiose catabolic system of Escherichia coli K12 is being used to study the role of cryptic genes in microbial evolution. Wild-type E. coli K12 do not utilize the β-glucoside sugars, arbutin, salicin and cellobiose. A Cel+ (cellobiose utilizing) mutant which grows on cellobiose, arbutin, and salicin was isolated previously from wild-type E. coli K12. Biochemical assays indicate that a cel structural gene (celT) specifies a single transport protein that is a β-glucoside specific enzyme of the phosphoenolpyruvate-dependent phosphotransferase system. The transport protein phosphorylates β-glucosides at the expense of phosphoenolpyruvate. A single phosphoglucosidase, specified by celH, hydrolyzes phosphorylated cellobiose, arbutin, and salicin. The genes of the cel system are expressed constitutively in the Cel+ mutant, whereas they are not expressed at a detectable level in the wild-type strain. The transport and hydrolase genes are simultaneously silenced or simultaneously expressed and thus constitute an operon. Cel+ strains which fail to utilize one or more β-glucosides express the transport system at a lower level than do Cel+ strains which grow on all three β-glucosides. Other strains inducibly express a gene which specifies transport of arbutin but not the other β-glucosides. The arbutin transport gene, arbT, maps outside of the cel locus.

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