Multi-site-specific endonucleases and the initiation of homologous genetic recombination in yeast.
The notion that homologous recombination is a regulated biological process is not a familiar one. In yeasts, homologous recombination and most site-specific ones are initiated by site-specific double-stranded breaks that are introduced within cis-acting elements for the recombination. On the other hand, yeasts have a group of site-specific endonucleases (multi-site-specific endonucleases) that have a number of cleavage sites on each DNA. One of them, Endo.SceI of S. cerevisiae, was shown to introduce double-stranded breaks at a number of well-defined sites on the mitochondrial DNA in vivo. An Endo.SceI-induced double-stranded break was demonstrated to induce homologous recombination in mitochondria. Like the case of homologous recombination of nuclear chromosomes, the double-stranded break induces gene conversion of both genetic markers flanking and in the proximity of the cleavage site, and the cleaved DNA acts as a recipient of genetic information from the uncleaved partner DNA. The 70 kDa-heat-shock protein (HSP70)-subunit of Endo.SceI and a general role of the HSP70 in the regulation of protein-folding suggest the regulation of nucleolytic activity of Endo.SceI.
Shibata
T
T
Laboratory of Cellular and Molecular Biology, Institute of Physical and Chemical Research (RIKEN), Saitama, Japan.
Nakagawa
K
K
Morishima
N
N
D001483:Base Sequence; D055592:Biophysical Phenomena; D001703:Biophysics; D004262:DNA Restriction Enzymes / Q000235:genetics*; D004271:DNA, Fungal / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics; D015252:Deoxyribonucleases, Type II Site-Specific / Q000235:genetics; D005800:Genes, Fungal; D008969:Molecular Sequence Data; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D015003:Yeasts / Q000201:enzymology* / Q000235:genetics*
D004271:DNA, Fungal; D004272:DNA, Mitochondrial; D029701:Saccharomyces cerevisiae Proteins; D004262:DNA Restriction Enzymes; C037725:SCEI protein, S cerevisiae; D015252:Deoxyribonucleases, Type II Site-Specific