A Holliday junction resolvase from Pyrococcus furiosus: functional similarity to Escherichia coli RuvC provides evidence for conserved mechanism of homologous recombination in Bacteria, Eukarya, and Archaea.
The Holliday junction is an essential intermediate of homologous recombination. RecA of Bacteria, Rad51 of Eukarya, and RadA of Archaea are structural and functional homologs. These proteins play a pivotal role in the formation of Holliday junctions from two homologous DNA duplexes. RuvC is a specific endonuclease that resolves Holliday junctions in Bacteria. A Holliday junction-resolving activity has been found in both yeast and mammalian cells. To examine whether the paradigm of homologous recombination apply to Archaea, we assayed and found the activity to resolve a synthetic Holliday junction in crude extract of Pyrococcus furiosus cells. The gene, hjc (Holliday junction cleavage), encodes a protein composed of 123 amino acids, whose sequence is not similar to that of any proteins with known function. However, all four archaea, whose total genome sequences have been published, have the homologous genes. The purified Hjc protein cleaved the recombination intermediates formed by RecA in vitro. These results support the notion that the formation and resolution of Holliday junction is the common mechanism of homologous recombination in the three domains of life.
Komori
K
K
Department of Molecular Biology, Biomolecular Engineering Research Institute, Suita, Osaka 565-0874, Japan.
Sakae
S
S
Shinagawa
H
H
Morikawa
K
K
Ishino
Y
Y
D000595:Amino Acid Sequence; D000818:Animals; D001105:Archaea / Q000235:genetics*; D001419:Bacteria / Q000235:genetics*; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D003001:Cloning, Molecular; D017124:Conserved Sequence; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D004706:Endodeoxyribonucleases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D029968:Escherichia coli Proteins; D045565:Holliday Junction Resolvases; D008322:Mammals; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D020027:Pyrococcus furiosus / Q000201:enzymology / Q000235:genetics*; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D045522:Recombinases; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D019895:Transposases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D011994:Recombinant Proteins; D045522:Recombinases; C069806:ruvC protein, E coli; D004247:DNA; D019895:Transposases; D004706:Endodeoxyribonucleases; D045565:Holliday Junction Resolvases; C112057:RusA protein, E coli