Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.6.3.14 (ATP synthase)
7,042 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The coupling step in the biosynthesis of ATP in biological systems is generally believed to involve an energy-requiring release of ATP bound to the beta-subunit of the ATP synthase complex. A molecular description of the ATP binding site on the beta-subunit is, therefore, critical to understanding the mechanism of coupling in the enzyme. Previously, we reported that a purified, bacterially expressed rat liver beta-subunit binds adenine nucleotides tightly and specifically (Garboczi, D. N., Hullihen, J. H., and Pedersen, P. L. (1988) J. Biol. Chem. 263, 15694-15698). In order to assess the contribution of various regions of the isolated beta-subunit to the ATP binding site we have systematically deleted four different regions: the N-terminal region, the Walker A consensus region, the Walker B consensus region (Walker, J. E., Saraste, M., Runswick, M. J., and Gay, N. (1982) EMBO J. 1, 945-951), and a "C" region, which, like the A and B regions, bears homology to adenylate kinase. Plasmids directing the expression of double deletions of A and B regions, and B and C regions were also constructed. In addition, 2 residues outside of these regions, His-177 and Tyr-345, which have been predicted to play a central role in nucleotide binding, were mutated. Rabbit antisera to synthetic peptides of the A and C regions verified the identity of the bacterially expressed mutant proteins. Seven of the eight mutant proteins overexpressed in Escherichia coli were resistant to E. coli proteases in the preparative stages, as predicted for compact folded proteins. Furthermore, circular dichroism spectropolarimetry revealed no profound structural alterations in the purified mutant proteins. Relative to the overexpressed full-length beta-subunit, the mutant lacking the A consensus region suffered a 30-fold loss of affinity for ATP and a loss of specificity for 2'(3')-O-(2,4,6-trinitrophenyl)adenosine 5'-triphosphate (TNP-ATP) over 2'(3')-O-(2,4,6-trinitrophenyl)adenosine 5'-monophosphate. The mutant proteins lacking either the N-terminal region or the B region exhibited nucleotide binding properties similar to the full-length beta-subunit, whereas the mutant protein lacking the C region suffered an order of magnitude reduction in affinity for ATP. The affinity of the A and B region double deletion was indistinguishable from the A region deletion in regard to TNP-ATP binding, while the double deletion mutant lacking the B and C regions was not stably expressed in the E. coli SE6004.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Mutational analysis of the consensus nucleotide binding sequences in the rat liver mitochondrial ATP synthase beta-subunit. 140 Mar 52

The gamma-subunit of mitochondrial ATP synthase is part of the extrinsic membrane sector of the enzyme F1-ATPase. It is a nuclear gene product. Complementary DNA clones encoding a precursor of the protein have been isolated from a bovine library. The initial partial clone was identified with a mixture of 32 synthetic oligonucleotides designed from the known protein sequence (Walker et al., 1985), and this isolate was then used to screen the library again in order to find a complete cDNA. The DNA sequence of a clone that encodes the entire mature protein has been established, and the deduced protein sequence agrees exactly with that determined by direct sequence analysis of protein isolated from bovine hearts (Walker et al., 1985). At the 3' ends of two independently isolated clones, alternative polyadenylation sites have been observed; otherwise, the DNA sequences of the clones are concordant. In common with many other mitochondrial proteins encoded in nuclear genes, the deduced protein sequence has an N-terminal extension that is absent from the mature protein. These presequences direct the protein to its appropriate mitochondrial compartment and are removed during the import process. The cDNA clone has been employed to isolate bovine genomic clones containing the gene for the gamma-subunit. From them, the DNA sequence has been established of a region encoding the mature protein and six amino acids in the presequence, but not the remainder of the proposed import sequence. This sequence extends over almost 10 kb and is divided into eight exons. Intron B between exons I and II contains a sequence that is related to long interspersed repetitive elements (LINEs) that have been described in other mammals. Human LINEs are usually flanked by directly repeated sequences with a poly(A) tract at their 3' ends, and these features are present in the bovine LINE which is truncated. This sequence contains an open reading frame encoding part of a protein that is closely related to a protein encoded in mouse LINEs, to reverse transcriptase, and to DNA binding proteins. We have also made a preliminary investigation by DNA hybridization of the number of sequences related to the bovine gene in both the bovine and human genomes. Under the experimental conditions employed, one fragment hybridized in digests of bovine DNA, and two to four bands were detected in digests of human DNA; these latter fragments have originated from either expressed genes or pseudogenes.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:ATP synthase from bovine mitochondria: complementary DNA sequence of the mitochondrial import precursor of the gamma-subunit and the genomic sequence of the mature protein. 252 51

The alpha-subunit of ATP synthase from mitochondria is a major component of the extrinsic membrane sector of the enzyme. It is encoded in nuclear DNA. A family of overlapping complementary DNA clones encoding its precursor has been isolated from a bovine library by using in the first instance a mixture of 128 synthetic oligonucleotides designed on the basis of the known protein sequence, and the sequence of the full-length cDNA has been determined. The deduced protein sequence shows that the alpha-subunit of ATP synthase has a presequence of 43 amino acids that is not present in the mature protein. Presumably it directs the protein into the mitochondrial matrix and is removed during the import process. The encoded protein sequence is also longer by one amino acid at its C-terminal end than the protein isolated from F1-ATPase, but this alanine residue may have been removed artifactually during release of the F1-ATPase particle from the inner mitochondrial membrane. With the exception of one uncertainty caused by an ambiguity at one position in the nucleotide sequence, the mature protein sequence encoded in the cDNA is exactly the same as the sequence determined previously by direct analysis of the protein isolated from bovine heart mitochondria [Walker et al. (1985) J. Mol. Biol. 184, 677-701]. The cDNA sequence differs in 158 nucleotides over a region of alignment of 1097 nucleotides from a partial cDNA for the alpha-subunit that has been isolated from a bovine cDNA derived from liver RNA [Breen (1988) Biochem. Biophys. Res. Commun. 152, 264-269].(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:ATP synthase from bovine mitochondria: complementary DNA sequence of the import precursor of a heart isoform of the alpha subunit. 252 57

The photosynthetic non-sulphur bacterium Rhodospirillum rubrum contains a cluster of five genes encoding the subunits of F1-ATPase [Falk, Hampe & Walker (1985) Biochem. J. 228, 391-407]. Transcription of these genes has been studied by two methods, transcriptional mapping with S1 nuclease and primer extension analysis. Thereby a 5'-end in RNA derived from this region has been demonstrated at a guanine residue 236 bases before the initiation codon of the gene for the delta-subunit, the first in this cluster. DNA sequences on the 5' side of this nucleotide show some similarity to promoters in Escherichia coli, but are not apparently related to sequences upstream of the Rhodopseudomonas blastica atp operon. A 3'-end in RNA derived from this gene cluster has been demonstrated by S1-nuclease mapping. This is found before a run of thymidylate residues in the DNA, on the 3' side of a region of dyad symmetry. In E. coli these features are characteristic of rho-independent transcriptional termination signals. It appears from these studies and from the organization of the genes that the five genes in the atp cluster may be co-transcribed from this promoter and that transcripts terminate at the region of dyad symmetry.
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PMID:Transcription of Rhodospirillum rubrum atp operon. 286 16

Clones encoding the proteolipid subunit 9 of the mitochondrial ATPase complex have been isolated from a lambda gt10 library of human liver cDNA sequences, using a probe of Neurospora crassa cDNA encoding subunit 9. From nucleotide sequence analysis it is concluded that the amino acid sequence of mature human subunit 9 is identical to that of its bovine counterpart. By comparing the sequence of two cDNA clones (denoted human 1 and 2) to those of two bovine cDNA clones (denoted P1 and P2) recently described by Gay and Walker (EMBO J. 4, 3519-3524, 1985) it is evident that there are close sequence relationships between human 1 and bovine P1, and between human 2 and bovine P2, although both human clones are truncated at their 5'-ends. Thus, as in bovine cells there appears to be at least two human genes encoding subunit 9.
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PMID:Human liver cDNA clones encoding proteolipid subunit 9 of the mitochondrial ATPase complex. 288 74

In order to assess the role of thiol groups in the Fo part of the ATP synthase in the coupling mechanism of ATP synthase, we have treated isolated Fo, extracted from beef heart Complex V with urea, with thiol reagents, primarily with diazenedicarboxylic acid bis-(dimethylamide) (diamide) but also with Cd2+ and N-ethylmaleimide. FoF1 ATP synthase was reconstituted by adding isolated F1 and the oligomycin-sensitivity-conferring-protein (OSCP) to Fo. The efficiency of reconstitution was assessed by determining the sensitivity to oligomycin of the ATP hydrolytic activity of the reconstituted enzyme. Contrary to Cd2+, incubation of diamide with Fo, before the addition of F1 and OSCP, induced a severe loss of oligomycin sensitivity, due to an inhibited binding of F1 to Fo. This effect was reversed by dithiothreitol. Conversely, if F1 and OSCP were added to Fo before diamide, no effect could be detected. These results show that F1 (and/or OSCP) protects Fo thiols from diamide and are substantiated by the finding that the oligomycin sensitivity of ATP hydrolysis activity of isolated Complex V was also unaltered by diamide. Gel electrophoresis of FoF1 ATP synthase, reconstituted with diamide-treated Fo, revealed that the loss of oligomycin sensitivity was directly correlated with diminution of band Fo 1 (or subunit b). Concomitantly a band appeared of approximately twice the molecular weight of subunit Fo 1. As this protein contains only 1 cysteine residue (Walker, J. E., Runswick, M. J., and Poulter, L. (1987) J. Mol. Biol. 197, 89-100), the effect of diamide is attributed to the formation of a disulfide bridge between two of these subunits. These results offer further evidence for the proposal, based on aminoacid sequence and structural analysis, that subunit Fo 1 of mammalian Fo is involved in the binding with F1 (Walker et al. (1987]. N-Ethylmaleimide affects oligomycin sensitivity to a lesser extent than diamide, suggesting that the mode of action of these reagents (and the structural changes induced in Fo) is different.
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PMID:ATP synthase complex from beef heart mitochondria. Role of the thiol group of the 25-kDa subunit of Fo in the coupling mechanism between Fo and F1. 290 33

The results of Section IV can be summarized in a simple ATP synthase model. This model implies that either the alpha or the beta subunits must be closer to the membrane. The work of Gao and Bauerlein (1987) indicates that the alpha subunits are closer to the membrane. Although the overall structure is more or less clear, important questions need to be clarified. First, the number and the arrangement of the subunits in the F0 part must be known. Second, the exact shape of F1, and particularly the shape of the large subunits needs to be elucidated. On the basis of fluorescence resonance energy transfer measurements by McCarty and Hammes (1987), a model was presented showing large oblong subunits. Such 'banana-shaped' subunits, which are also presented in the many phantasy models (e.g. Walker et al., 1982), are very unlikely in view of the electron microscopical results, although the large subunits do not need to be exactly spherical. The third and most interesting central question is on the changes in the structure that take place during the different steps in the synthesis of ATP. It can now be taken as proven that the energy transmitted to the ATP synthase is used to induce a conformational change in the latter enzyme, in such a way as to bring about the energy-requiring dissociation of already synthesized ATP (Penefsky, 1985 and reviewed in Slater, 1987). But the way in which the three parts of the ATP synthase are involved is completely unknown. It is rather puzzling that such a long distance exists between the catalytic sites, which are on the interface of the alpha and beta subunits and the F0 part where the proton movements occur, which, according to Mitchell's theory (1961), is the driving force for the synthesis of ATP. Perhaps alternative mechanisms such as the collision hypothesis formulated by Herweijer et al. (1985) are more realistic in describing the mechanism of ATP synthesis. It would bring the complexes I and V close together, not only in the artificial way treated in this paper, but in a useful way for energy conversion.
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PMID:Electron microscopy and image analysis of the complexes I and V of the mitochondrial respiratory chain. 290 40

Reaction of the photoaffinity label 8-azido-[2-3H] ATP with bovine heart mitochondrial F1-ATPase abolishes its enzyme activity; inhibition is prevented by ATP (Wagenvoord, R.J., van der Kraan, I., and Kemp, A. (1977) Biochim. Biophys. Acta 460, 17-24). More than 65% of the radioactivity is associated with the beta-subunit and about 25% with the alpha-chains. Radioactivity in the beta-subunit is localized in two specific regions. One corresponds to residues 1-12 (Runswick, M.J., and Walker, J.E. (1983) J. Biol. Chem. 258, 3081-3089), a region which is nonessential for catalysis. Radioactivity in the second region is localized predominantly on three amino acids, lysine 301, isoleucine 304, and tyrosine 311. It seems likely that these residues are found in the vicinity of the ATP binding site of F1-ATPase.
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PMID:The sites of labeling of the beta-subunit of bovine mitochondrial F1-ATPase with 8-azido-ATP. 622 27

The amino acid sequence of the beta-subunit of bovine heart mitochondrial ATP synthase has been determined by protein sequence analysis. The polypeptide chain of 478 amino acids is blocked at its NH2 terminal. Comparison of this sequence with sequences of the corresponding proteins from Escherichia coli (Saraste, M., Gay, N.J., Eberle, A., Runswick, M.J., and Walker, J.E. (1981) Nucleic Acids Res. 9, 5287-5296) and maize and spinach chloroplasts Krebbers, E.T., Larrinua, I. M., McIntosh, L., and Bogorad, L. (1982) Nucleic Acids Res. 10, 4985-5002; Kurawski, G., Bottomley, W., and Whitfield, P.R. (1982) Proc. Natl. Acad. Sci. U.S.A. 79, 6260-6264) shows that the protein is highly conserved. 70% of residues are identical in E. coli and beef mitochondria. This contrasts with some of the other subunits in the enzyme complex which are much less conserved.
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PMID:The amino acid sequence of the beta-subunit of ATP synthase from bovine heart mitochondria. 629 22

Glu-beta 185 of the Escherichia coli H(+)-ATPase (ATP synthase) beta subunit was replaced by 19 different amino acid residues. The rates of multisite (steady state) catalysis of all the mutant membrane ATPases except Asp- beta 185 were less than 0.2% of the wild type one; the Asp- beta 185 enzyme exhibited 15% (purified) and 16% (membrane-bound) ATPase activity. The purified inactive Cys- beta 185 F1-ATPase recovered substantial activity after treatment with iodoacetate in the presence of MgCl2; maximal activity was obtained upon the introduction of about 3 mol of carboxymethyl residues/mol of F1. The divalent cation dependences of the S-carboxymethyl- beta 185 and Asp- beta 185 ATPase activities were altered from that of the wild type. The Asp- beta 185, Cys- beta 185, S-carboxymethyl-beta 185, and Gln- beta 185 enzymes showed about 130, 60, 20, and 50% of the wild type unisite catalysis rates, respectively. The S-carboxymethyl- beta 185 and Asp- beta 185 enzymes showed altered divalent cation sensitivities, and the S-carboxymethyl- beta 185 enzyme showed no Mg2+ inhibition. Unlike the wild type, the two mutant enzymes showed low sensitivities to azide, which stabilizes the enzyme Mg-ADP complex. These results suggest that Glu- beta 185 may form a Mg2+ binding site, and its carboxyl moiety is essential for catalytic cooperativity. Consistent with this model, the bovine glutamate residue corresponding to Glu- beta 185 is located close to the catalytic site in the higher order structure (Abrahams, J.P., Leslie, A.G.W., Lutter, R ., and Walker, J.E. (1994) Nature 370, 621-628)
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PMID:Beta subunit Glu-185 of Escherichia coli H(+)-ATPase (ATP synthase) is an essential residue for cooperative catalysis. 759 42


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