Functional citric acid cycle in an arcA mutant of Escherichia coli during growth with nitrate under anoxic conditions

1998 ◽  
Vol 170 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Corinna Prohl ◽  
Birgit Wackwitz ◽  
Dorina Vlad ◽  
G. Unden
Keyword(s):  
Escherichia Coli ◽  
Citric Acid ◽  
Citric Acid Cycle ◽  
Acid Cycle ◽  
Anoxic Conditions ◽  
Arca Mutant

scholarly journals The ms2io6A37 Modification of tRNA inSalmonella typhimurium Regulates Growth on Citric Acid Cycle Intermediates

1998 ◽  
Vol 180 (12) ◽  
pp. 3144-3151 ◽  
Author(s):  
Britt C. Persson ◽  
Ólafur Ólafsson ◽  
Hans K. Lundgren ◽  
Lars Hederstedt ◽  
Glenn R. Björk
Keyword(s):  
Escherichia Coli ◽  
Citric Acid ◽  
Salmonella Typhimurium ◽  
Gene Product ◽  
Respiratory Chain ◽  
Citric Acid Cycle ◽  
Dicarboxylic Acids ◽  
Acid Cycle ◽  
E Coli ◽  
Isopentenyl Adenosine

ABSTRACT The modified nucleoside 2-methylthio-N-6-isopentenyl adenosine (ms2i6A) is present in position 37 (adjacent to and 3′ of the anticodon) of tRNAs that read codons beginning with U except tRNA I,V Ser inEscherichia coli. In Salmonella typhimurium, 2-methylthio-N-6-(cis-hydroxy)isopentenyl adenosine (ms2io6A; also referred to as 2-methylthio cis-ribozeatin) is found in tRNA, most likely in the species that have ms2i6A in E. coli. Mutants (miaE) of S. typhimurium in which ms2i6A hydroxylation is blocked are unable to grow aerobically on the dicarboxylic acids of the citric acid cycle. Such mutants have normal uptake of dicarboxylic acids and functional enzymes of the citric acid cycle and the aerobic respiratory chain. The ability of S. typhimurium to grow on succinate, fumarate, and malate is dependent on the state of modification in position 37 of those tRNAs normally having ms2io6A37 and is not due to a second cellular function of tRNA (ms2io6A37)hydroxylase, themiaE gene product. We suggest that S. typhimurium senses the hydroxylation status of the isopentenyl group of the tRNA and will grow on succinate, fumarate, or malate only if the isopentenyl group is hydroxylated.

EFFECT OF SERUM GONADOTROPHIN ON DEHYDROGENASES OF THE CITRIC ACID CYCLE IN THE OVARY OF THE RAT

1963 ◽  
Vol 42 (4) ◽  
pp. 480-484 ◽  
Author(s):  
B. Eckstein ◽  
R. Landsberg
Keyword(s):  
Citric Acid ◽  
Citric Acid Cycle ◽  
Age Groups ◽  
Succinic Dehydrogenase ◽  
Immature Rat ◽  
Acid Cycle ◽  
Immature Rats ◽  
Rat Ovary

ABSTRACT The succinic, malic and isocitric dehydrogenases in the ovary of immature and mature, normal and serum gonadotrophin injected rats were examined. The Qo2 of these enzymes were markedly enhanced in the gonadotrophin injected rats of both age groups, except in the case of succinic dehydrogenase in the ovary of the immature rats, where a slight non-significant decrease was noted. It is concluded that in the mature rat ovary, gonadotrophin administration stimulates the activity of all the examined dehydrogenases of the citric acid cycle, whereas in the immature rat ovary, at least the isocitric- and malic dehydrogenases are thus stimulated.

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