scholarly journals Oxidative phosphorylation in Escherichia coli. Characterization of mutant strains in which F1-ATPase contains abnormal β-subunits

1983 ◽  
Vol 210 (2) ◽  
pp. 395-403 ◽  
Author(s):  
A E Senior ◽  
L Langman ◽  
G B Cox ◽  
F Gibson
Keyword(s):  
Escherichia Coli ◽  
Ionic Strength ◽  
Atpase Activity ◽  
Atp Synthesis ◽  
Beta Subunit ◽  
F1 Atpase ◽  
Dependent Atpase ◽  
Mutant Strains ◽  
Synthesis Activity ◽  
Low Ionic Strength

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.

scholarly journals The uncA gene codes for the α-subunit of the adenosine triphosphatase of Escherichia coli. Electrophoretic analysis of uncA mutant strains

1979 ◽  
Vol 180 (1) ◽  
pp. 103-109 ◽  
Author(s):  
A E Senior ◽  
J A Downie ◽  
G B Cox ◽  
F Gibson ◽  
L Langman ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Ionic Strength ◽  
Adenosine Triphosphatase ◽  
Alpha Subunit ◽  
Subunit Structure ◽  
Net Charge ◽  
Α Subunit ◽  
F1 Atpase ◽  
Mutant Strains ◽  
Low Ionic Strength

Four mutant strains of Escherichia coli which lack membrane-bound adenosine triphosphatase activity were shown by genetic-complementation tests to carry mutations in the uncA gene. A soluble inactive F1-ATPase aggregate was released from the membranes of three of the uncA mutant strains by low-ionic-strength washing, and purified by procedures developed for the purification of F1-ATPase from normal strains. Analysis of the subunit structure by two-dimensional gel electrophoresis indicated that the F1-ATPase in strains carrying the uncA401 or uncA453 alleles had a subunit structure indistinguishable from normal F1-ATPase. In contrast, the F1-ATPase from the strain carrying the uncA447 allele contained an alpha-subunit of normal molecular weight, but abnormal net charge. Membranes from strains carrying the uncA450 allele did not have F1-ATPase aggregates that could be solubilized by low-ionic-strength washing. However, a partial dipolid strain carrying both the uncA+ and uncA450 alleles formed an active F1-ATPase aggregate which could be solubilized by low-ionic-strength washing of the membranes and which contained two types of alpha-subunit, one of which was normal and the other had abnormal net charge. It is concluded that the uncA gene codes for the alpha-subunit of the adenosine triphosphatase.

scholarly journals Properties of membranes from mutant strains of Escherichia coli in which the β-subunit of the adenosine triphosphatase is abnormal

1979 ◽  
Vol 180 (1) ◽  
pp. 111-118 ◽  
Author(s):  
A E Senior ◽  
D R Fayle ◽  
J A Downie ◽  
F Gibson ◽  
G B Cox
Keyword(s):  
Escherichia Coli ◽  
Atpase Activity ◽  
Mutant Allele ◽  
Adenosine Triphosphatase ◽  
Beta Subunit ◽  
Beta Subunits ◽  
F1 Atpase ◽  
Mutant Strains ◽  
Membrane Bound ◽  
Phenotypic Variations

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.

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
Keyword(s):  
Escherichia Coli ◽  
Atpase Activity ◽  
Beta Subunit ◽  
F1 Atpase

scholarly journals Lysine 155 in beta-subunit is a catalytic residue of Escherichia coli F1 ATPase.

1993 ◽  
Vol 268 (10) ◽  
pp. 6989-6994
Author(s):  
A.E. Senior ◽  
S. Wilke-Mounts ◽  
M.K. al-Shawi
Keyword(s):  
Escherichia Coli ◽  
Beta Subunit ◽  
Catalytic Residue ◽  
F1 Atpase

scholarly journals Activation of the Adenosine Triphosphatase of Limulus polyphemus Actomyosin by Tropomyosin

1972 ◽  
Vol 59 (4) ◽  
pp. 375-387 ◽  
Author(s):  
William Lehman ◽  
Andrew G. Szent-Györgyi
Keyword(s):  
Ionic Strength ◽  
Atpase Activity ◽  
Adenosine Triphosphatase ◽  
Limulus Polyphemus ◽  
Muscle Tropomyosin ◽  
Low Ionic Strength ◽  
Full Activation

Purified actin does not stimulate the adenosine triphosphatase (ATPase) activity of Limulus myosin greatly. The ATPase activity of such reconstituted preparations is only about one-fourth the ATPase of myofibrils or of natural actomyosin. Actin preparations containing tropomyosin, however, activate Limulus myosin fully. Both the tropomyosin and the actin preparations appear to be pure when tested by different techniques. Tropomyosin combines with actin but not with myosin and full activation is reached at a tropomyosin-to-actin ratio likely to be present in muscle. Tropomyosin and actin of several different animals stimulate the ATPase of Limulus myosin. Tropomyosin, however, is not required for the ATPases of scallop and rabbit myosin which are fully activated by pure actin alone. Evidence is presented that Limulus myosin, in the presence of ATP at low ionic strength, has a higher affinity for actin modified by tropomyosin than for pure actin.

scholarly journals Evidence from Insect Fibrillar Muscle about the Elementary Contractile Process

1967 ◽  
Vol 50 (6) ◽  
pp. 139-156 ◽  
Author(s):  
J. W. S. Pringle
Keyword(s):  
Ionic Strength ◽  
Atpase Activity ◽  
Striated Muscle ◽  
Contractile Activity ◽  
High Elasticity ◽  
Flight Muscles ◽  
The Cross ◽  
Cross Bridges ◽  
Low Ionic Strength ◽  
Water Bugs

Bundles of myofibrils prepared from the dorsal longitudinal flight muscles of giant water bugs show oscillatory contractile activity in solutions of low ionic strength containing ATP and 10-8-10-7 M Ca2+. This is due to delay between changes of length and changes of tension under activating conditions. The peculiarities of insect fibrillar muscle which give rise to this behavior are (1) the high elasticity of relaxed myofibrils, (2) a smaller degree of Ca2+ activation of ATPase activity in unstretched myofibrils and extracted actomyosin, and (3) a direct effect of stretch on ATPase activity. It is shown that the cross-bridges of striated muscle are probably formed from the heads of three myosin molecules and that in insect fibrillar muscle the cycles of mechanochemical energy conversion in the cross-bridges can be synchronized by imposed changes of length. This material is more suitable than vertebrate striated muscle for a study of the nature of the elementary contractile process.

scholarly journals A 72,000-mol-wt protein from tomato inhibits rabbit acto-S-1 ATPase activity.

1983 ◽  
Vol 96 (6) ◽  
pp. 1761-1765 ◽  
Author(s):  
M Vahey
Keyword(s):  
Skeletal Muscle ◽  
Ionic Strength ◽  
Atpase Activity ◽  
Rabbit Skeletal Muscle ◽  
Ion Concentration ◽  
Actin Binding ◽  
Molar Ratio ◽  
Reversible Inhibitor ◽  
Skeletal Muscle Myosin ◽  
Low Ionic Strength

Tomato activation inhibiting protein (AIP) is a molecule of an apparent molecular weight of 72,000 that co-purifies with tomato actin. In an assay system containing rabbit skeletal muscle F-actin and rabbit skeletal muscle myosin subfragment-1 (myosin S-1), tomato AIP dissociated the acto-S-1 complex in the absence of Mg+2ATP and inhibited the ability of F-actin to activate the low ionic strength Mg+2ATPase activity of myosin S-1. At a molar ratio of 5 actin to 1 AIP, a 50% inhibition of the actin-activated Mg+2ATPase activity of myosin S-1 was observed. The inhibition can be reversed by raising the calcium ion concentration to 1 X 10(-5) M. The AIP had no effect on the basal low ionic strength Mg+2ATPase activity of myosin S-1 in the absence of actin. The protein did not bind directly to actin nor did it cause depolymerization or aggregation of F-actin but appeared, instead, to interact with the actin binding site on myosin S-1. Since AIP is a potent, reversible inhibitor of the rabbit acto-S-1 ATPase activity, it is postulated that it may be responsible for the low levels of actin activation exhibited by tomato F-actin fractions containing the AIP.

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