Studies on ATPase(GTPase) intrinsic to E. coli ribosomes.
(1) Escherichia coli 70S ribosomes showed intrinsic ATPase and GTPase activities, although they were much lower than those of rat liver ribosomes. The latter activity was higher than the former one. (2) The ATPase activity was inhibited by GTP and GMP-P(NH)P, and the GTPase activity was inhibited by ATP and AMP-P(NH)P, indicating a close relationship between the two enzymes. (3) Elongation components alone or in combination enhanced the ATPase activity, indicating the possible correlation of ribosomal ATPase with elongational components. (4) Vanadate at the concentrations that did not inhibit the GTPase activities of EF-Tu and EF-G, depressed the poly(U)-dependent polyphe synthesis, suggesting that ribosomal ATPase (GTPase) participates in peptide elongation by inducing positive conformational changes of ribosomes required for the attachment of elongational components.
Institute for Gene Expression, Dobashi Kyoritsu Hospital, Dobashi, Matsuyama, Ehime 790-0032, Japan.
K
K
Ogata
R
R
Ohno
R
R
Morishita
Y
Y
Endo
A
A
Wada
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000266:Adenylyl Imidodiphosphate / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004926:Escherichia coli / Q000201:enzymology*; D020558:GTP Phosphohydrolases / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000494:pharmacology; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D020653:Peptide Elongation Factor G / Q000494:pharmacology; D010444:Peptide Elongation Factor Tu / Q000494:pharmacology; D012270:Ribosomes / Q000201:enzymology*
D004791:Enzyme Inhibitors; D020653:Peptide Elongation Factor G; D000266:Adenylyl Imidodiphosphate; D006165:Guanylyl Imidodiphosphate; D006160:Guanosine Triphosphate; D000251:Adenosine Triphosphatases; D020558:GTP Phosphohydrolases; D010444:Peptide Elongation Factor Tu