Suppression of a dicarboxylic acid transport mutant phenotype in Escherichia coli K12

1972 ◽  
Vol 264 (3) ◽  
pp. 522-529 ◽  
Author(s):  
W KAY
Keyword(s):  
Escherichia Coli ◽  
Dicarboxylic Acid ◽  
Mutant Phenotype ◽  
Acid Transport ◽  
Escherichia Coli K12 ◽  
Transport Mutant

scholarly journals Succinate uptake and related proton movements in Escherichia coli K12

1975 ◽  
Vol 152 (3) ◽  
pp. 647-654 ◽  
Author(s):  
S J Gutowski ◽  
H Rosenberg
Keyword(s):  
Escherichia Coli ◽  
Dicarboxylic Acid ◽  
Transport System ◽  
Dicarboxylic Acids ◽  
Acid Transport ◽  
Cationic Form ◽  
Whole Cells ◽  
Escherichia Coli K12 ◽  
Proton Uptake

1. The apparent Km values for succinate uptake by whole cells of Escherichia coli K12 depend on pH in the range 6.5-7.4.2. Uptake of succinate in lightly buffered medium is accompanied by proton uptake. 3. The apparent Km values for succinate uptake and for succinate-induced proton uptake are similar. 4. Approximately two protons enter the cell with each succinate molecule. 5. The pattern of inhibition of succinate uptake is similar to that of succinate-induced proton uptake. 6. Uptake of fumarate and malate, which share the succinate-transport system, is also accompanied by the uptake of approximately two protons per molecule of fumarate or malate. 7. Uptake of aspartate by the dicarboxylic acid-transport system is accompanied by the uptake of approximatley two protons per molecule of asparatate. 8. It is concluded that uptake of dicarboxylic acids by the dicarboxylic acid-transport system is obligatorily coupled to proton uptake such that succinate, malate and fumarate are taken up in electroneutral form and asparate is taken up in cationic form. 9. These results are consistent with, though they do not definitely prove, the energization of succinate uptake of the deltapH.

scholarly journals Characterization and in Vivo Cloning of prlC, a Suppressor of Signal Sequence Mutations in Escherichia coli K12

Genetics ◽  
1987 ◽  
Vol 116 (4) ◽  
pp. 513-521
Author(s):  
Nancy J Trun ◽  
Thomas J Silhavy
Keyword(s):  
Escherichia Coli ◽  
Genetic Mapping ◽  
Signal Sequence ◽  
Illegitimate Recombination ◽  
Mutant Phenotype ◽  
E Coli ◽  
Physical Location ◽  
Sequence Deletion ◽  
New Alleles

ABSTRACT The prlC gene of E. coli was originally identified as an allele, prlC1, which suppresses certain signal sequence mutations in the genes for several exported proteins. We have isolated six new alleles of prlC that also confer this phenotype. These mutations can be placed into three classes based on the degree to which they suppress the lamBsignal sequence deletion, lamBs78. Genetic mapping reveals that the physical location of the mutations in prlC correlates with the strength of the suppression, suggesting that different regions of the gene can be altered to yield a suppressor phenotype. We also describe an in vivo cloning procedure using λplacMu9H. The procedure relies on transposition and illegitimate recombination to generate a specialized transducing phage that carries prlC1. This method should be applicable to any gene for which there is a mutant phenotype.

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