TY - JOUR
T1 - Escherichia coli H+-ATPase
T2 - Role of the δ subunit in binding F1 to the F0 sector
AU - Jounouchi, Masayoshi
AU - Takeyama, Michiyasu
AU - Chaiprasert, Pawinee
AU - Noumi, Takato
AU - Moriyama, Yoshinori
AU - Maeda, Masatomo
AU - Futai, Masamitsu
N1 - Funding Information:
1 This research was supported in part by grants from the Ministry of Education, Science, and Culture of Japan, grants for a research program on the “Creation of New Materials through Intelligent Design” (ISIR, Osaka University), and grants from the Human Frontier Science Program. ’ To whom correspondence should be addressed.
PY - 1992/2/1
Y1 - 1992/2/1
N2 - The roles of the Escherichia coli H+-ATPase (F0F1) δ subunit (177 amino acid residues) was studied by analyzing mutants. The membranes of nonsense (Gln-23 → end, Gln-29 → end, Gln-74 → end) and missense (Gly-150 → Asp) mutants had very low ATPase activities, indicating that the δ subunit is essential for the binding of the F1 portion to F0. The Gln-176 → end mutant had essentially the same membrane-bound activity as the wild type, whereas in the Val-174 → end mutant most of the ATPase activity was in the cytoplasm. Thus Val-174 (and possibly Leu-175 also) was essential for maintaining the structure of the subunit, whereas the two carboxyl terminal residues Gln-176 and Ser-177 were dispensable. Substitutions were introduced at various residues (Thr-11, Glu-26, Asp-30, Glu-42, Glu-82, Arg-85, Asp-144, Arg-154, Asp-161, Ser-163), including apparently conserved hydrophilic ones. The resulting mutants had essentially the same phenotypes as the wild type, indicating that these residues do not have any significant functional role(s). Analysis of mutations (Gly-150 → Asp, Pro, or Ala) indicated that Gly-150 itself was not essential, but that the mutations might affect the structure of the subunit. These results suggest that the overall structure of the δ subunit is necessary, but that individual residues may not have strict functional roles.
AB - The roles of the Escherichia coli H+-ATPase (F0F1) δ subunit (177 amino acid residues) was studied by analyzing mutants. The membranes of nonsense (Gln-23 → end, Gln-29 → end, Gln-74 → end) and missense (Gly-150 → Asp) mutants had very low ATPase activities, indicating that the δ subunit is essential for the binding of the F1 portion to F0. The Gln-176 → end mutant had essentially the same membrane-bound activity as the wild type, whereas in the Val-174 → end mutant most of the ATPase activity was in the cytoplasm. Thus Val-174 (and possibly Leu-175 also) was essential for maintaining the structure of the subunit, whereas the two carboxyl terminal residues Gln-176 and Ser-177 were dispensable. Substitutions were introduced at various residues (Thr-11, Glu-26, Asp-30, Glu-42, Glu-82, Arg-85, Asp-144, Arg-154, Asp-161, Ser-163), including apparently conserved hydrophilic ones. The resulting mutants had essentially the same phenotypes as the wild type, indicating that these residues do not have any significant functional role(s). Analysis of mutations (Gly-150 → Asp, Pro, or Ala) indicated that Gly-150 itself was not essential, but that the mutations might affect the structure of the subunit. These results suggest that the overall structure of the δ subunit is necessary, but that individual residues may not have strict functional roles.
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U2 - 10.1016/0003-9861(92)90005-H
DO - 10.1016/0003-9861(92)90005-H
M3 - Article
C2 - 1530999
AN - SCOPUS:0026556885
VL - 292
SP - 376
EP - 381
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
SN - 0003-9861
IS - 2
ER -