Binding of [14C]aurovertin D to Escherichia coli F1-ATPase and the isolated .beta. subunit. Correlation with inhibition of the ATPase activity

Biochemistry ◽  
1983 ◽  
Vol 22 (14) ◽  
pp. 3485-3492 ◽  
Author(s):  
Jean Paul Issartel ◽  
Gerard Klein ◽  
Michel Satre ◽  
Pierre V. Vignais
1983 ◽  
Vol 210 (2) ◽  
pp. 395-403 ◽  
Author(s):  
A E Senior ◽  
L Langman ◽  
G B Cox ◽  
F Gibson

To facilitate study of the role of the beta-subunit in the membrane-bound proton-translocating ATPase of Escherichia coli, we identified mutant strains from which an F1-ATPase containing abnormal beta-subunits can be purified. Seventeen strains of E. coli, characterized by genetic complementation tests as carrying mutations in the uncD gene (which codes for the beta-subunit), were studied. The majority of these strains (11) were judged to be not useful, as their membranes lacked ATPase activity, and were either proton-permeable as prepared or remained proton-impermeable after washing with buffer of low ionic strength. A further two strains were of a type not hitherto reported, in that their membranes had ATPase activity, were proton-impermeable as prepared, and were not rendered proton-permeable by washing in buffer of low ionic strength. Presumably in these two strains F1-ATPase is not released in soluble form by this procedure. F1-ATPase of normal molecular size were purified from strains AN1340 (uncD478), AN937 (uncD430), AN938 (uncD431) and AN1543 (uncD484). F1-ATPase from strain AN1340 (uncD478) had 15% of normal specific Mg-dependent ATPase activity and 22% of normal ATP-synthesis activity. The F1-ATPase preparations from strains AN937, AN938 and AN1543 had respectively 1.7%, 1.8% and 0.2% of normal specific Mg-dependent ATPase activity, and each of these preparations had very low ATP-synthesis activity. The yield of F1-ATPase from the four strains described was almost twice that obtained from a normal haploid strain. The kinetics of Ca-dependent ATPase activity were unusual in each of the four F1-ATPase preparations. It is likely that these four mutant uncD F1-ATPase preparations will prove valuable for further experimental study of the F1-ATPase catalytic mechanism.


1979 ◽  
Vol 180 (1) ◽  
pp. 111-118 ◽  
Author(s):  
A E Senior ◽  
D R Fayle ◽  
J A Downie ◽  
F Gibson ◽  
G B Cox

Five uncoupled mutant strains of Escherichia coli carrying mutations in the uncD gene have been studied. In each of these mutant strains the beta-subunit of the F1 portion of the membrane-bound adenosine triphosphatase is abnormal. In one of the mutant strains (carrying the uncD12 allele) in F1-ATPase aggregate was formed which was purified and found to have low ATPase activity. ATPase activity was absent in the other four strains and the abnormal beta-subunits were tightly bound to the membranes. However, membranes from these strains exhibited various proton permeabilities as indicated by NADH-dependent atebrin-fluorescence quenching and bound different amounts of normal F1-ATPase. The amounts of reconstitution of energy-linked reactions after the addition of normal F1-ATPase also varied depending on the mutant allele. It is apparent that considerable phenotypic variations can occur between strains carrying mutations in the same unc gene.


1993 ◽  
Vol 268 (10) ◽  
pp. 6989-6994
Author(s):  
A.E. Senior ◽  
S. Wilke-Mounts ◽  
M.K. al-Shawi

1989 ◽  
Vol 259 (2) ◽  
pp. 421-426 ◽  
Author(s):  
F A Kironde ◽  
D Parsonage ◽  
A E Senior

ATP synthesis by oxidative phosphorylation in Escherichia coli occurs in catalytic sites on the beta-subunits of F1-ATPase. Random mutagenesis of the beta-subunit combined with phenotypic screening is potentially important for studies of the catalytic mechanism. However, when applied to haploid strains, this approach is hampered by a preponderance of mutants in which assembly of F1-ATPase in vivo is defective, precluding enzyme purification. Here we mutagenized plasmids carrying the uncD (beta-subunit) gene with hydroxylamine or N-methyl-N'-nitro-N-nitrosoguanidine and isolated, by phenotypic screening and complementation tests, six plasmids carrying mutant uncD alleles. When the mutant plasmids were used to transform a suitable uncD- strain, assembly of F1-ATPase in vivo occurred in each case. Moreover, in one case (beta Gly-223----Asp) F1-ATPase assembly proceeded although it had previously been reported that this mutation, when present on the chromosome of a haploid strain, prevented assembly of the enzyme in vivo. Therefore, this work demonstrates an improved approach for random mutagenesis of the F1-beta-subunit. Six new mutant uncD alleles were identified: beta Cys-137----Tyr; beta Gly-142----Asp; beta Gly-146----Ser; beta Gly-207----Asp; beta-Gly-223----Asp; and a double mutant beta Pro-403----Ser,Gly-415----Asp which we could not separate. The first five of these lie within or very close to the predicted catalytic nucleotide-binding domain of the beta-subunit. The double mutant lies outside this domain; we speculate that the region around residues beta 403-415 is part of an alpha-beta intersubunit contact surface. Membrane ATPase and ATP-driven proton pumping activities were impaired by all six mutations. Purified F1-ATPase was obtained from each mutant and shown to have impaired specific ATPase activity.


1983 ◽  
Vol 216 (1) ◽  
pp. 143-150 ◽  
Author(s):  
G B Cox ◽  
D A Jans ◽  
F Gibson ◽  
L Langman ◽  
A E Senior ◽  
...  

The effect on the function of the Escherichia coli F1F0-ATPase of the substitution of leucine-31 by phenylalanine in the c-subunit of the enzyme was examined. The assembly of the mutant c-subunit requires an increased gene dosage [Jans, Fimmel, Langman, James, Downie, Senior, Ash, Gibson & Cox (1983) Biochem. J. 211, 717-726], and this was achieved by incorporation of the uncE408 or uncE463 alleles on to F-plasmids or multicopy plasmids. Membranes from strains carrying either the uncE463 or uncE408 alleles on F-plasmids or multicopy plasmids were capable of carrying out oxidative phosphorylation. In particular, membranes from strain AN1928 (pAN162, uncE463) gave phosphorylation rates and P/O ratios equal to or greater than those obtained for the control strain AN1460 (pAN45, unc+). However, the mutant membranes, on removal of the F1-ATPase, appeared to be proton-impermeable. The ATPase activity of the mutant membranes was also resistant to the inhibitor dicyclohexylcarbodi-imide.


Biochemistry ◽  
1990 ◽  
Vol 29 (45) ◽  
pp. 10387-10393 ◽  
Author(s):  
Robert Aggeler ◽  
Janet Mendel-Hartvig ◽  
Roderick A. Capaldi

1987 ◽  
Vol 262 (17) ◽  
pp. 8022-8026 ◽  
Author(s):  
D Parsonage ◽  
S Wilke-Mounts ◽  
A E Senior

1983 ◽  
Vol 213 (2) ◽  
pp. 451-458 ◽  
Author(s):  
A L Fimmel ◽  
D A Jans ◽  
L Langman ◽  
L B James ◽  
G R Ash ◽  
...  

The uncE410 allele differs from the normal uncE gene in that C leads to T base changes occur at nucleotides 190 and 191, resulting in proline at position 64 in the c-subunit of the F1F0-ATPase being replaced by leucine. Two partial-revertant strains were isolated in which alanine-20 of the c-subunit was replaced by proline, owing to a G leads to C base change at nucleotide 58. These c-subunits, coded for by the uncE501 and uncE502 alleles, therefore contained two amino acid changes, namely proline-64 leads to leucine, and alanine-20 leads to proline. Membranes prepared from the partial-revertant strains lacked ATP-dependent atebrin-fluorescence-quenching activity but were able to carry out oxidative phosphorylation. The ATPase activity of the F1-ATPase was inhibited when bound to membranes from strains carrying the uncE410, uncE501 and uncE502 alleles. It is concluded that a bend in the helix axis in one of the arms of the c-subunit hairpin structure is required for integration of the c-subunit into a functional F1F0-ATPase.


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