Schizosaccharomyces pombe exo1 is involved in the same mismatch repair pathway as msh2 and pms1.
Besides the MutLS-like system, Schizosaccharomyces pombe has an additional pathway of mismatch repair. This minor pathway, producing short excision tracts, repairs C/C and, with lower efficiency, other mismatches also. We investigated the involvement of the exo1+, msh2+ and pms1+ genes in the two pathways. The exo1+ gene encodes a 5' to 3' exonuclease, while msh2+ and pms1+ are homologs of Escherichia coli mutS and mutL, respectively. Intragenic two-factor crosses showed that exo1+, msh2+ and pms1+ are involved in the major, but not in the C/C-correcting, pathway. Post-meiotic segregation frequencies and mitotic mutation rates in single and double mutants supported this finding. Furthermore, msh2 delta was epistatic over exo1 delta, and the ExoI enzyme is likely to be redundant with other exonucleases.
Rudolph
C
C
Institute of General Microbiology, University of Bern, Baltzerstrasse 4, CH-3012 Bern, Switzerland.
Fleck
O
O
Kohli
J
J
D002352:Carrier Proteins; D004260:DNA Repair / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005090:Exodeoxyribonucleases / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism*; D005785:Gene Conversion; D005800:Genes, Fungal / Q000235:genetics; D008540:Meiosis / Q000235:genetics; D008938:Mitosis / Q000235:genetics; D051718:MutS Homolog 2 Protein; D011995:Recombination, Genetic; D012568:Schizosaccharomyces / Q000235:genetics* / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins
D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D029702:Schizosaccharomyces pombe Proteins; D005090:Exodeoxyribonucleases; C028450:exodeoxyribonuclease I; D051718:MutS Homolog 2 Protein; C489752:msh2 protein, S pombe