Evidence is presented that chemotaxis requires
ATP or a closely related metabolite, in addition to its known requirements of
ATP for synthesis of
S-adenosylmethionine (
AdoMet) and maintenance of the proton motive force. Previous studies demonstrated a loss of tumbling and chemotaxis, and depletion of
ATP when hisF auxotrophs of Salmonella typhimurium are starved for
histidine (Galloway, R. J., and Taylor, B. L. (1980) J. Bacteriol. 144, 1068-1075). In the present study, intracellular [
AdoMet], membrane potential, and [
ATP] were measured in a hisF mutant of S. typhimurium. Membrane potential, determined from partitioning of [3H]
tetraphenylphosphonium ion between the inside and the outside of the cell, was about -150 mV at pH 7.6, and did not decrease in
histidine starvation but was slightly increased. The concentration of
AdoMet decreased from 0.4 mM to 0.3 mM during
starvation but when
cycloleucine, an inhibitor of
AdoMet synthetase, was used to decrease [
AdoMet] by a similar amount in
histidine-fed cells there was little change in tumbling frequency. Intracellular [
ATP] was reduced from 4.5 mM to less than 0.2 mM by
histidine starvation. About 0.2 mM
ATP was necessary for spontaneous tumbling. A similar [
ATP] was required for tumbling in
arsenate-treated cells.
Adenine at concentrations as low as 20 nM caused a transient increase in both tumbling frequency and [
ATP] in
histidine-starved cells. Thus, out of three parameters tested, only the intracellular [
ATP] correlated with changes in tumbling frequency in the
histidine-starved cells.