[ATPase activity and K+ transport in membranes of anaerobically grown trk-mutants of Escherichia coli].
A notable (twofold) increase in N,N'-dicyclohexylcarbodiimide (DCCD)-sensitive ATPase activity at increasing concentrations of K+ ion--from zero to 100 mM was found in isolated membranes of anaerobically grown E. coli. This was also observed during changing of Rb+ concentration (but not that of Na+, CL- or NO3-) and only in the wild precursor strain and trkG (but not in trkA, trkE, or trkH mutants). The DCCD-sensitive ATPase activity did not depend on K+ concentration in membranes of bacteria grown in the presence of NaNO3. TrkG or trkH mutants of E. coli with unc-deletions displayed a slight ATPase activity which was insensitive to DCCD. The growth of the trkG mutant, unlike other trk mutants, did not depend on K+ concentration above 0.4 mM. In this case accumulation of K+ in this mutant under positive osmotic shock was notably higher. These results suggest that K(+)-dependent DCCD-sensitive ATPase activity in membranes of anaerobically grown bacteria depends critically on the functioning of F1F0-ATPase and Trk of the K+ uptake system and may be explained by a direct relationship between these transport systems. It is also probable that the trkG gene has no functional activity in anaerobically grown bacteria.
Trchunian
A A
AA
Vasilian
A V
AV
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D001692:Biological Transport; D002462:Cell Membrane / Q000201:enzymology / Q000378:metabolism; D004024:Dicyclohexylcarbodiimide / Q000494:pharmacology; D004789:Enzyme Activation; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D009154:Mutation; D011188:Potassium / Q000378:metabolism*
D004024:Dicyclohexylcarbodiimide; D000251:Adenosine Triphosphatases; D011188:Potassium
ATPaznaia aktivnost' i transport K+ v membranakh anaérobno vyrashchennykh trk-mutantov Escherichia coli.