ATPase of Rhodospirillum rubrum requires three functional copies of beta subunit as determined by radiation inactivation analysis.
Radiation inactivation analysis yielded a functional unit of 170 +/- 26 kDa as beta subunit of ATPase was irradiated and then reconstituted to beta-depleted chromatophores of Rhodospirillum rubrum. A functional size of 132 +/- 17 kDa for the beta-depleted ATPase moiety involved in ATP hydrolysis reaction was also determined. When both purified beta subunit and beta-depleted chromatophore were irradiated separately, reconstituted, and then activity measured, the functional mass was 312 +/- 50 kDa. Our compelling evidence directly indicates that three functional copies of beta subunits were required for ATP hydrolysis.
Chien
L F
LF
Institute of Radiation Biology, College of Nuclear Science, National Tsing Hua University, Hsin Chu, Taiwan, Republic of China.
Wu
J J
JJ
Tzeng
C M
CM
Pan
R L
RL
D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000378:metabolism* / Q000528:radiation effects; D000255:Adenosine Triphosphate / Q000378:metabolism; D020130:Bacterial Chromatophores / Q000201:enzymology; D005720:Gamma Rays; D006868:Hydrolysis; D008970:Molecular Weight; D012247:Rhodospirillum rubrum / Q000201:enzymology*
D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases