Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.6.1.3 (ATPase)
65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We present DNA sequence data from a 35,364 bp region on the left arm of chromosome VII of Saccharomyces cerevisiae. This region contains 19 open reading frames (ORFs). ORF G1821 corresponds to the RAD54 gene involved in repair and recombination (Emery et al., 1991). G1810 is identical to the ACE1 gene sequenced by Szczypka and Thiele (1989), required for copper-inducible transcription of the CUP1 gene. The first 693 bp on the minus strand represent part of the 3' non-coding region from the P-type ATPase gene PMR1, previously sequenced by Rudolph et al. (1989), which is identical to the SSC1 gene (Smith et al., 1988). G1845 corresponds to the RCK1 protein kinase gene from S. cerevisiae (Dahlkvist and Sunnerhagen, 1994). G1861 is almost identical to the alpha-mannosidase gene AMS1 reported by Yoshihisa and Anraku (1989) and G1864 has 100% identity with the yeast CAL1 gene (Ohya et al., 1989)/CDC43 gene (Johnson et al., 1990) which is involved in control of cell polarity. This region also contains a gene specifying a Leu-tRNA precursor and a remnant of a tau element. ORF G1880 shows some similarity to the S. cerevisiae SNF2, STH1 and NPS1 genes and to the human ERCC1 gene. A 93 bp region shows similarity to yeast EST sequenced by Burns et al. (1994). None of the remaining ORFs has similarity to any sequence within the databases screened.
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PMID:DNA sequence analysis of a 35 kb segment from Saccharomyces cerevisiae chromosome VII reveals 19 open reading frames including RAD54, ACE1/CUP2, PMR1, RCK1, AMS1 and CAL1/CDC43. 858 24

Many proteins of the SNF2 family, which share a similar DNA-dependent ATPase/putative helicase domain, are involved in global transcriptional control and processing of DNA damage. We report here the partial cloning and characterization of 89B helicase, a gene encoding a new Drosophila melanogaster member of the SNF2 family. 89B Helicase protein shows a high degree of homology in its ATPase/helicase domain to the global transcriptional activators SNF2 and Brahma and to the DNA repair proteins ERCC6 and RAD54. It is, however, most strikingly similar to the Saccharomyces cerevisiae protein Mot1, a transcriptional repressor with many target genes for which no homologue has yet been described. 89B helicase is expressed throughout fly development and its large transcript encodes a >200 kDa protein. Staining with anti-89B Helicase antibodies reveals that the protein is present uniformly in early embryos and then becomes localized to the ventral nerve cord and brain. On the polytene chromosomes, 89B Helicase is bound to several hundred specific sites that are randomly distributed. The homology of 89B Helicase to Mot1, its widespread developmental expression and its large number of targets on the polytene chromosomes of larval salivary gland cells suggest that 89B Helicase may play a role in chromosomal metabolism, particularly global transcriptional regulation.
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PMID:Expanding the Mot1 subfamily: 89B helicase encodes a new Drosophila melanogaster SNF2-related protein which binds to multiple sites on polytene chromosomes. 877 90

The yeast SWI2/SNF2 polypeptide is a subunit of the SWI/SNF protein complex that is required for many transcriptional activators to function in a chromatin context. SWI2 is believed to be the founding member of a new subfamily of DNA-stimulated ATPases/DNA helicases that includes proteins that function in DNA repair (RAD5, RAD16, ERCC6), recombination (RAD54), transcription (MOT1, ISWI, brm, BRG1, hBRM) and cell cycle control (STH1). We have created a set of 16 mutations within the SWI2 ATPase domain and have analyzed the functional consequences of these mutations in vivo. We have identified residues within each of the seven ATPase motifs that are required for SWI2 function. We have also identified crucial residues that are interspersed between the known ATPase motifs. In contrast, we identify other highly conserved residues that appear to be dispensable for SWI2 function. We also find that single amino acid changes in ATPase motifs IV and VI lead to a dominant negative phenotype. None of the 12 SWI2 mutations that disrupt SWI2 activity in vivo alter the assembly of the SWI/SNF complex. These studies provide an invaluable framework for biochemical analysis of the SWI2 ATPase and for functional analysis of other SWI2 family members.
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PMID:Functional analysis of the DNA-stimulated ATPase domain of yeast SWI2/SNF2. 887 45

The Saccharomyces cerevisiae RAD51 and RAD54 genes are both required for the occurrence of homologous recombination and for the repair of double-stranded DNA breaks. Previous studies have indicated that Rad51 protein, together with the single-stranded DNA-binding factor replication protein A (RPA), can promote the formation of heteroduplex DNA, which is a key intermediate in homologous recombination. Here we report the purification of the Rad54 protein to near homogeneity and the biochemical testing of its molecular function. We find that Rad54 protein possesses a double-stranded DNA-dependent ATPase activity, and that it interacts with the Rad51 protein. Addition of Rad54 protein to reactions containing Rad51 strongly stimulates the rate of pairing between homologous single-stranded and double-stranded DNA molecules. We conclude that Rad54 acts to overcome kinetic impediments that would limit homologous DNA pairing between recombining chromosomes in vivo.
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PMID:Catalysis of homologous DNA pairing by yeast Rad51 and Rad54 proteins. 959 Jun 97

DNA double-strand break repair through the RAD52 homologous recombination pathway in the yeast Saccharomyces cerevisiae requires, among others, the RAD51, RAD52, and RAD54 genes. The biological importance of homologous recombination is underscored by the conservation of the RAD52 pathway from fungi to humans. The critical roles of the RAD52 group proteins in the early steps of recombination, the search for DNA homology and strand exchange, are now becoming apparent. Here, we report the purification of the human Rad54 protein. We showed that human Rad54 has ATPase activity that is absolutely dependent on double-stranded DNA. Unexpectedly, the ATPase activity appeared not absolutely required for the DNA repair function of human Rad54 in vivo. Despite the presence of amino acid sequence motifs that are conserved in a large family of DNA helicases, no helicase activity of human Rad54 was observed on a variety of different DNA substrates. Possible functions of human Rad54 in homologous recombination that couple the energy gained from ATP hydrolysis to translocation along DNA, rather than disruption of base pairing, are discussed.
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PMID:The human RAD54 recombinational DNA repair protein is a double-stranded DNA-dependent ATPase. 977 52

RAD54 is an important gene in the RAD52 group that controls recombinational repair of DNA damage in Saccharomyces cerevisiae. Rad54p is a DNA-dependent ATPase and shares seven conserved sequence motifs with proteins of the Swi2p/Snf2p family. Genetic analysis of mutations in motif IA, the putative ATP-binding fold of Rad54p, demonstrated the functional importance of this motif. Overexpression of these mutant proteins resulted in strong, dominant-negative effects on cell survival. High levels of full-length wild-type Rad54p or specific parts of Rad54p also resulted in negative effects, dependent on the ploidy of the host cell. This differential effect was not under a/alpha mating-type control. Deletion of the RAD54 gene led to a small but significant increase in the mutation rate. However, the negative overexpression effects in haploid cells could not be explained by an accumulation of (recessive) lethal mutations. All negative overexpression effects were found to be enhanced under genotoxic stress. We suggest that the negative overexpression effects are the result of unbalanced protein-protein interactions, indicating that Rad54p is involved in multiple interactions, dependent on the physiological situation. Diploid wild-type cells contained an estimated 7000 Rad54p molecules/cell, whereas haploid cells about 3500/cell. Rad54p levels were highest in actively growing cells compared to stationary phase cells. Rad54 protein levels were found to be elevated after DNA damage.
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PMID:Specific negative effects resulting from elevated levels of the recombinational repair protein Rad54p in Saccharomyces cerevisiae. 1039 42

Saccharomyces cerevisiae RAD54 gene functions in the formation of heteroduplex DNA, a key intermediate in recombination processes. Rad54 is monomeric in solution, but forms a dimer/oligomer on DNA. Rad54 dimer/oligomer alters the conformation of the DNA double helix in an ATP-dependent manner, as revealed by a change in the DNA linking number in a topoisomerase I-linked reaction. DNA conformational alteration does not occur in the presence of non-hydrolyzable ATP analogues, nor when mutant rad54 proteins defective in ATP hydrolysis replace Rad54. Accordingly, the Rad54 ATPase activity is shown to be required for biological function in vivo and for promoting Rad51-mediated homologous DNA pairing in vitro. Taken together, the results are consistent with a model in which a Rad54 dimer/oligomer promotes nascent heteroduplex joint formation via a specific interaction with Rad51 protein and an ability to transiently unwind duplex DNA.
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PMID:Yeast Rad54 promotes Rad51-dependent homologous DNA pairing via ATP hydrolysis-driven change in DNA double helix conformation. 1050 8

RAD54 is an important member of the RAD52 group of genes that carry out recombinational repair of DNA damage in the yeast Saccharomyces cerevisiae. Rad54 protein is a member of the Snf2/Swi2 protein family of DNA-dependent/stimulated ATPases, and its ATPase activity is crucial for Rad54 protein function. Rad54 protein and Rad54-K341R, a mutant protein defective in the Walker A box ATP-binding fold, were fused to glutathione-S-transferase (GST) and purified to near homogeneity. In vivo, GST-Rad54 protein carried out the functions required for methyl methanesulfonate sulfate (MMS), UV, and DSB repair. In vitro, GST-Rad54 protein exhibited dsDNA-specific ATPase activity. Rad54 protein stimulated Rad51/Rpa-mediated DNA strand exchange by specifically increasing the kinetics of joint molecule formation. This stimulation was accompanied by a concurrent increase in the formation of heteroduplex DNA. Our results suggest that Rad54 protein interacts specifically with established Rad51 nucleoprotein filaments before homology search on the duplex DNA and heteroduplex DNA formation. Rad54 protein did not stimulate DNA strand exchange by increasing presynaptic complex formation. We conclude that Rad54 protein acts during the synaptic phase of DNA strand exchange and after the formation of presynaptic Rad51 protein-ssDNA filaments.
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PMID:Rad54 protein stimulates heteroduplex DNA formation in the synaptic phase of DNA strand exchange via specific interactions with the presynaptic Rad51 nucleoprotein filament. 1129 36

The RAD52 epistasis group genes are involved in homologous recombination, and they are conserved from yeast to humans. We have cloned a novel human gene, RAD54B, which is homologous to yeast and human RAD54. Human Rad54B (hRad54B) shares high homology with human Rad54 (hRad54) in the central region containing the helicase motifs characteristic of the SNF2/SWI2 family of proteins, but the N-terminal domain is less conserved. In yeast, another RAD54 homolog, TID1/RDH54, plays a role in recombination. Tid1/Rdh54 interacts with yeast Rad51 and a meiosis-specific Rad51 homolog, Dmc1. The N-terminal domain of hRad54B shares homology with that of Tid1/Rdh54, suggesting that Rad54B may be the human counterpart of Tid1/Rdh54. We purified the hRad54 and hRad54B proteins from baculovirus-infected insect cells and examined their biochemical properties. hRad54B, like hRad54, is a DNA-binding protein and hydrolyzes ATP in the presence of double-stranded DNA, though its rate of ATP hydrolysis is lower than that of hRad54. Human Rad51 interacts with hRad54 and enhances its ATPase activity. In contrast, neither human Rad51 nor Dmc1 directly interacts with hRad54B. Although hRad54B is the putative counterpart of Tid1/Rdh54, our findings suggest that hRad54B behaves differently from Tid1/Rdh54.
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PMID:Human Rad54B is a double-stranded DNA-dependent ATPase and has biochemical properties different from its structural homolog in yeast, Tid1/Rdh54. 1188 32

The RAD54 gene of Saccharomyces cerevisiae encodes a conserved dsDNA-dependent ATPase of the Swi2/Snf2 family with a specialized function during recombinational DNA repair. Here we analyzed the consequences of the loss of Rad54 function in vegetative (mitotic) cells. Mutants in RAD54 exhibited drastically reduced rates of spontaneous intragenic recombination but were proficient for spontaneous intergenic recombinant formation. The intergenic recombinants likely arose by a RAD54-independent pathway of break-induced replication. Significantly increased rates of spontaneous chromosome loss for diploid rad54/rad54 cells were identified in several independent assays. Inter estingly, the increase in chromosome loss appeared to depend on the presence of a homolog. In addition, the rate of complex genetic events involving chromosome loss were drastically increased in diploid rad54/rad54 cells. Together, these data suggest a role for Rad54 protein in the repair of spontaneous damage, where in the absence of Rad54 protein, homologous recombination is initiated but not properly terminated, leading to misrepair and chromosome loss.
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PMID:Genome instability in rad54 mutants of Saccharomyces cerevisiae. 1256 Apr 98


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