학술논문

F0 part of the ATP synthase from Escherichia coli. Influence of subunits a, and b, on the structure of subunit c.
Document Type
Academic Journal
Author
Steffens K; Universität Osnabrück, Fachbereich Biologie/Chemie, Mikrobiologie, Federal Republic of Germany.; Hoppe JAltendorf K
Source
Publisher: Blackwell Science Ltd. on behalf of the Federation of European Biochemical Societies Country of Publication: England NLM ID: 0107600 Publication Model: Print Cited Medium: Print ISSN: 0014-2956 (Print) Linking ISSN: 00142956 NLM ISO Abbreviation: Eur J Biochem Subsets: MEDLINE
Subject
Language
English
ISSN
0014-2956
Abstract
Four different sets of proteoliposomes were prepared from F0, subunit c, a complex of subunits a and c (ac complex) and an ac complex supplemented with subunit b. Only liposomes containing intact F0 or all subunits of F0 were active in proton translocation and F1 binding [Schneider, E. and Altendorf, K. (1985) EMBO J. 4, 515-518]. The conformation of subunit c in the different preparations was analyzed by labelling the proteoliposomes with the hydrophobic photoactivatable reagent 3-(trifluoromethyl)-3-(m-[125I]iodophenyl)diazirine ([125I]TID). Subsequent isolation and Edman degradation of this polypeptide revealed distinct radioactive labelling patterns over the entire amino acid sequence. In the F0 complex and in the ac complex subunit c retains a labelling pattern which is related to that found in TID-labelled membrane vesicles of Escherichia coli [Hoppe et al. (1984) Biochemistry 23, 5610-5616]. In the absence of subunit a, considerably more and different amino acid residues of subunit c are modified. The labelling data are discussed in relation to structural aspects of F0 and functional properties of proteoliposomes reconstituted with F0 or individual subunits.