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Titolo:
THE SUBUNIT-DELTA SUBUNIT-B DOMAIN OF THE ESCHERICHIA-COLI F(1)F(0)ATPASE - THE B-SUBUNITS INTERACT WITH F1 AS A DIMER AND THROUGH THE DELTA-SUBUNIT
Autore:
RODGERS AJW; WILKENS S; AGGELER R; MORRIS MB; HOWITT SM; CAPALDI RA;
Indirizzi:
UNIV OREGON,INST MOL BIOL EUGENE OR 97403 UNIV OREGON,INST MOL BIOL EUGENE OR 97403 UNIV SYDNEY,DEPT PHARM SYDNEY NSW 2006 AUSTRALIA AUSTRALIAN NATL UNIV,JOHN CURTIN SCH MED RES,DIV BIOCHEM & MOL BIOL CANBERRA ACT 2601 AUSTRALIA
Titolo Testata:
The Journal of biological chemistry
fascicolo: 49, volume: 272, anno: 1997,
pagine: 31058 - 31064
SICI:
0021-9258(1997)272:49<31058:TSSDOT>2.0.ZU;2-W
Fonte:
ISI
Lingua:
ENG
Soggetto:
ADENOSINE-TRIPHOSPHATASE; ATP-SYNTHASE; H+-ATPASE; OXIDATIVE-PHOSPHORYLATION; EPSILON-SUBUNITS; CATALYTIC SITES; GAMMA-SUBUNITS; UNC OPERON; C-SUBUNIT; F1;
Tipo documento:
Article
Natura:
Periodico
Citazioni:
34
Recensione:
Indirizzi per estratti:
Citazione:
A.J.W. Rodgers et al., "THE SUBUNIT-DELTA SUBUNIT-B DOMAIN OF THE ESCHERICHIA-COLI F(1)F(0)ATPASE - THE B-SUBUNITS INTERACT WITH F1 AS A DIMER AND THROUGH THE DELTA-SUBUNIT", The Journal of biological chemistry, 272(49), 1997, pp. 31058-31064

Abstract

The delta and b subunits are both involved in binding the F-1, to theF-0, part in the Escherichia coli ATP synthase (ECF1F0,). The interaction of the purified delta subunit and the isolated hydrophilic domainof the b subunit (b(sol),,,) has been studied here. Purified delta binds to b(sol),,, weakly in solution, as indicated by NMR studies and protease protection experiments. On F-1,, i.e. in the presence of ECF1-delta,, delta, and b(sol),,, interact strongly, and a complex of ECF1 . b(sol), b(sol),,, can be isolated by native gel electrophoresis. Both delta subunit and b(sol),,, are protected from trypsin cleavage in this complex. In contrast, the delta subunit is rapidly degraded by theprotease when bound to ECF1, when b(sol),,, is absent. The interaction of b(sol),,, with ECF1, involves the C-terminal domain of delta as delta((1-134)), cannot replace intact delta in the binding experiments. As purified, b(sol),,, is a stable dimer with 80% alpha helix. A monomeric form of b(sol),,, can be obtained by introducing the mutation A128D (Howitt, S. M., Rodgers, A. J.,W., Jeffrey, P. D., and Cox, G., B. (1996) J. Biol. Chem. 271, 7038-7042). Monomeric b(sol),,, has less cu helix, i.e. only 58%, is much more sensitive to trypsin cleavage than dimer, and unfolds at much lower temperatures than the dimer in circular dichroism melting studies, indicating a less stable structure. The b(sol),,, dimer, but not monomer, binds to delta in ECF1,. To examine whether subunit b is a monomor or dimer in intact ECF1F0,, CuCl2, was used to induce cross-link formation in the mutants bS60C, bQ104C, bA128C, bG131C, and bS146C. With the exception of bS60C, CuCl2, treatment resulted in formation of b subunit dimers in all mutants. Cross-linking yield was independent of nucleotide conditions and did not affect ATPase activity. These results show the b subunit to be dimeric for a large portion of the C terminus, with residues 124-131 likely forming a pair of parallel alpha helices.

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Documento generato il 21/09/20 alle ore 01:28:15