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)

Replication factor C (RFC) is a five-subunit DNA polymerase accessory protein that functions as a structure-specific, DNA-dependent ATPase. The ATPase function of RFC is activated by proliferating cell nuclear antigen. RFC was originally purified from human cells on the basis of its requirement for simian virus 40 DNA replication in vitro. A functionally homologous protein complex from Saccharomyces cerevisiae, called ScRFC, has been identified. Here we report the cloning, by either peptide sequencing or by sequence similarity to the human cDNAs, of the S. cerevisiae genes RFC1, RFC2, RFC3, RFC4, and RFC5. The amino acid sequences are highly similar to the sequences of the homologous human RFC 140-, 37-, 36-, 40-, and 38-kDa subunits, respectively, and also show amino acid sequence similarity to functionally homologous proteins from Escherichia coli and the phage T4 replication apparatus. All five subunits show conserved regions characteristic of ATP/GTP-binding proteins and also have a significant degree of similarity among each other. We have identified eight segments of conserved amino acid sequences that define a family of related proteins. Despite their high degree of sequence similarity, all five RFC genes are essential for cell proliferation in S. cerevisiae. RFC1 is identical to CDC44, a gene identified as a cell division cycle gene encoding a protein involved in DNA metabolism. CDC44/RFC1 is known to interact genetically with the gene encoding proliferating cell nuclear antigen, confirming previous biochemical evidence of their functional interaction in DNA replication.
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PMID:Characterization of the five replication factor C genes of Saccharomyces cerevisiae. 765 83

The RFC4 gene encoding the 37-kDa subunit of Saccharomyces cerevisiae replication factor C (RF-C) has been cloned and sequenced. The RFC4 gene encodes a 323-amino acid polypeptide with a molecular weight of 36,126. The deduced amino acid sequence of the RFC4 gene shows high sequence similarity to the other two small subunits of yeast RF-C and the three small subunits of human RF-C (35-60% identity, 55-78% similarity). The similarity is greatest with the 40-kDa subunit of human RF-C (also called Activator 1). Despite the presence of a MluI cell cycle box in the regulatory region of the RFC4 gene, the steady state levels of its mRNA do not change significantly during the yeast mitotic cell cycle. The RFC4 gene is essential for yeast viability and is located on the left arm of chromosome XV, between the SUF1 and ADH1 genes. The essential role of this as well as the other small subunits of RF-C indicates a unique function for each of these subunits, despite their apparent structural redundancy. Rfc4p was overexpressed in Escherichia coli. Despite the presence of consensus ATPase motifs in the primary amino acid sequence, no discernible biochemical function could be ascribed to the purified protein. However, Rfc4p formed a tight complex with the product of the RFC3 gene which encodes the ATPase of RF-C.
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PMID:Cloning and characterization of the essential Saccharomyces cerevisiae RFC4 gene encoding the 37-kDa subunit of replication factor C. 806 32

The conserved lysine in the Walker A motif of the ATP-binding domain encoded by the yeast RFC1, RFC2, RFC3, and RFC4 genes was mutated to glutamic acid. Complexes of replication factor C with a N-terminal truncation (Delta2-273) of the Rfc1 subunit (RFC) containing a single mutant subunit were overproduced in Escherichia coli for biochemical analysis. All of the mutant RFC complexes were capable of interacting with PCNA. Complexes containing a rfc1-K359E mutation were similar to wild type in replication activity and ATPase activity; however, the mutant complex showed increased susceptibility to proteolysis. In contrast, complexes containing either a rfc2-K71E mutation or a rfc3-K59E mutation were severely impaired in ATPase and clamp loading activity. In addition to their defects in ATP hydrolysis, these complexes were defective for DNA binding. A mutant complex containing the rfc4-K55E mutation performed as well as a wild type complex in clamp loading, but only at very high ATP concentrations. Mutant RFC complexes containing rfc2-K71R or rfc3-K59R, carrying a conservative lysine --> arginine mutation, had much milder clamp loading defects that could be partially (rfc2-K71R) or completely (rfc3-K59R) suppressed at high ATP concentrations.
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PMID:ATP utilization by yeast replication factor C. III. The ATP-binding domains of Rfc2, Rfc3, and Rfc4 are essential for DNA recognition and clamp loading. 1143 54

Replication factor C (RFC) is a heteropentameric AAA+ protein clamp loader of the proliferating cell nuclear antigen (PCNA) processivity factor. The prokaryotic homologue, gamma complex, is also a heteropentamer, and structural studies show the subunits are arranged in a circle. In this report, Saccharomyces cerevisiae RFC protomers are examined for their interaction with each other and PCNA. The data lead to a model of subunit order around the circle. A characteristic of AAA+ oligomers is the use of bipartite ATP sites in which one subunit supplies a catalytic arginine residue for hydrolysis of ATP bound to the neighboring subunit. We find that the RFC(3/4) complex is a DNA-dependent ATPase, and we use this activity to determine that RFC3 supplies a catalytic arginine to the ATP site of RFC4. This information, combined with the subunit arrangement, defines the composition of the remaining ATP sites. Furthermore, the RFC(2/3) and RFC(3/4) subassemblies bind stably to PCNA, yet neither RFC2 nor RFC4 bind tightly to PCNA, indicating that RFC3 forms a strong contact point to PCNA. The RFC1 subunit also binds PCNA tightly, and we identify two hydrophobic residues in RFC1 that are important for this interaction. Therefore, at least two subunits in RFC make strong contacts with PCNA, unlike the Escherichia coli gamma complex in which only one subunit makes strong contact with the beta clamp. Multiple strong contact points to PCNA may reflect the extra demands of loading the PCNA trimeric ring onto DNA compared with the dimeric beta ring.
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PMID:Replication factor C clamp loader subunit arrangement within the circular pentamer and its attachment points to proliferating cell nuclear antigen. 1453 Feb 60