Energizing effects of illumination on the reactivities of lysine residues of the gamma subunit of chloroplast ATP synthase.
Incubation of chloroplast thylakoids with pyridoxal 5'-phosphate for a short time (5 s) modified the lysine residues of the gamma subunit of ATP synthase. Energization of thylakoids by illumination increased the reactivity of Lys24 by a factor of three and decreased the reactivity of Lys30 to 60%. The reactivities of these residues reached their maximum and minimum values, respectively, within 1 s after the onset of illumination. Illumination of thylakoids increased the reactivities of Lys222 and Lys231 in two steps by a factor of three. The first step was completed within 1 s and the second step was completed 20-30 s after the onset of illumination. In the presence of 10 mM NH4Cl, illumination of thylakoids did not change the reactivities of these lysine residues. These results suggest that the Lys24- and Lys30-containing region of the gamma subunit changes its conformation rapidly in response to delta mu H+ and that the Lys222- and Lys231-containing region of the gamma subunit changes its conformation in two steps in response to delta mu H+ formation.
Komatsu-Takaki
M
M
Department of Chemistry, Faculty of Pharmaceutical Sciences, Teikyo University, Japan.
D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry; D002417:Cattle; D002736:Chloroplasts / Q000201:enzymology* / Q000502:physiology; D006863:Hydrogen-Ion Concentration; D008239:Lysine / Q000737:chemistry; D008564:Membrane Potentials; D008969:Molecular Sequence Data; D010777:Photochemistry; D010788:Photosynthesis; D006180:Proton-Translocating ATPases / Q000737:chemistry* / Q000378:metabolism; D011732:Pyridoxal Phosphate / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D018724:Spinacia oleracea
D001426:Bacterial Proteins; D011732:Pyridoxal Phosphate; D006180:Proton-Translocating ATPases; D008239:Lysine