The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)



Gene Review

PSO2  -  Pso2p

Saccharomyces cerevisiae S288c

Synonyms: DNA cross-link repair protein PSO2/SNM1, SNM1, YM9375.06C, YMR137C
Welcome! If you are familiar with the subject of this article, you can contribute to this open access knowledge base by deleting incorrect information, restructuring or completely rewriting any text. Read more.

Disease relevance of PSO2

  • We have used recombinant SNM1 constructs in an Escherichia coli (E. coli) expression system to demonstrate that the yeast gene encodes a 5'-exonuclease [1].

High impact information on PSO2

  • The gene product bears amino acid sequence similarity to two better understood protein families, namely the PSO2 (SNM1) DNA interstrand crosslink repair proteins and the 73-kD subunit of mRNA 3' end cleavage and polyadenylation specificity factor (CPSF73) [2].
  • The rejoining of single- and double-strand breaks is not only dependent on the product of the RAD51 gene (as shown by others) but also of the PSO2 gene [3].
  • DNA interstrand cross-link repair in the Saccharomyces cerevisiae cell cycle: overlapping roles for PSO2 (SNM1) with MutS factors and EXO1 during S phase [4].
  • In addition, the interstrand cross-link repair gene PSO2 plays a role in end joining hairpin ends that is not seen in repair of linearized plasmids and may be involved in positioning transposase cleavage at the transposon ends [5].
  • We also identified and disrupted the S. pombe homologue of the Saccharomyces cerevisiae SNM1/PSO2 ICL repair gene and found that this activity is required for normal resistance to cross-linking agents, but not other forms of DNA damage [6].

Biological context of PSO2

  • Here we establish a novel overlapping function for PSO2 with MutS mismatch repair factors and the 5'-3' exonuclease Exo1 in the repair of DNA ICLs, which is confined to S phase [4].
  • Therefore, PSO2, EXO1, and MSH2 also appear to have overlapping roles in the processing of some forms of endogenous DNA damage that occur at an irreversibly collapsed replication fork [4].
  • Mutants in RAD6 and PSO2 genes showed the same transformation efficiency with 8-MOP plus UVA treated plasmid as wild-type cells suggesting that these latter pathways involved in mutagenesis are not operating on plasmid DNA although required for the repair of 8-MOP photoadducts induced in genomic DNA [7].
  • Molecular structure of the DNA cross-link repair gene SNM1 (PSO2) of the yeast Saccharomyces cerevisiae [8].
  • The action of the PSO2 gene product specific for the repair of DNA crosslinks in recombination induction is discussed and compared to the actions of the excision repair genes RAD1 and RAD2 [9].

Associations of PSO2 with chemical compounds


Regulatory relationships of PSO2


Other interactions of PSO2


Analytical, diagnostic and therapeutic context of PSO2

  • Molecular cloning of SNM1, a yeast gene responsible for a specific step in the repair of cross-linked DNA [14].
  • Surprisingly, no inducibility of SNM1 was found after treatment with DNA-damaging agents in strains without an intact DUN1 gene, while regulation seems unchanged in sad1 mutants [13].
  • In the yeast Saccharomyces cerevisiae, allelism between the pso1-1 and the rev3-1 mutants on the one hand and the pso2-1 and snm1 mutants on the other, is demonstrated by the comparison of phenotypes, complementation tests and meiotic segregation analysis [15].


  1. The yeast Snm1 protein is a DNA 5'-exonuclease. Li, X., Hejna, J., Moses, R.E. DNA Repair (Amst.) (2005) [Pubmed]
  2. A candidate prostate cancer susceptibility gene at chromosome 17p. Tavtigian, S.V., Simard, J., Teng, D.H., Abtin, V., Baumgard, M., Beck, A., Camp, N.J., Carillo, A.R., Chen, Y., Dayananth, P., Desrochers, M., Dumont, M., Farnham, J.M., Frank, D., Frye, C., Ghaffari, S., Gupte, J.S., Hu, R., Iliev, D., Janecki, T., Kort, E.N., Laity, K.E., Leavitt, A., Leblanc, G., McArthur-Morrison, J., Pederson, A., Penn, B., Peterson, K.T., Reid, J.E., Richards, S., Schroeder, M., Smith, R., Snyder, S.C., Swedlund, B., Swensen, J., Thomas, A., Tranchant, M., Woodland, A.M., Labrie, F., Skolnick, M.H., Neuhausen, S., Rommens, J., Cannon-Albright, L.A. Nat. Genet. (2001) [Pubmed]
  3. The fate of 8-methoxypsoralen photoinduced crosslinks in nuclear and mitochondrial yeast DNA: comparison of wild-type and repair-deficient strains. Magaña-Schwencke, N., Henriques, J.A., Chanet, R., Moustacchi, E. Proc. Natl. Acad. Sci. U.S.A. (1982) [Pubmed]
  4. DNA interstrand cross-link repair in the Saccharomyces cerevisiae cell cycle: overlapping roles for PSO2 (SNM1) with MutS factors and EXO1 during S phase. Barber, L.J., Ward, T.A., Hartley, J.A., McHugh, P.J. Mol. Cell. Biol. (2005) [Pubmed]
  5. Microhomology-dependent end joining and repair of transposon-induced DNA hairpins by host factors in Saccharomyces cerevisiae. Yu, J., Marshall, K., Yamaguchi, M., Haber, J.E., Weil, C.F. Mol. Cell. Biol. (2004) [Pubmed]
  6. Schizosaccharomyces pombe checkpoint response to DNA interstrand cross-links. Lambert, S., Mason, S.J., Barber, L.J., Hartley, J.A., Pearce, J.A., Carr, A.M., McHugh, P.J. Mol. Cell. Biol. (2003) [Pubmed]
  7. Repair of exogenous (plasmid) DNA damaged by photoaddition of 8-methoxypsoralen in the yeast Saccharomyces cerevisiae. Magaña-Schwencke, N., Averbeck, D. Mutat. Res. (1991) [Pubmed]
  8. Molecular structure of the DNA cross-link repair gene SNM1 (PSO2) of the yeast Saccharomyces cerevisiae. Richter, D., Niegemann, E., Brendel, M. Mol. Gen. Genet. (1992) [Pubmed]
  9. Effects of post-treatment incubation on recombinogenesis in incision-proficient and incision-deficient strains of Saccharomyces cerevisiae: II. Recombinogenesis after the photoaddition of furocoumarins. Saeki, T., Machida, I. J. Radiat. Res. (1991) [Pubmed]
  10. Saccharomyces cerevisiae lacking Snm1, Rev3 or Rad51 have a normal S-phase but arrest permanently in G2 after cisplatin treatment. Grossmann, K.F., Ward, A.M., Moses, R.E. Mutat. Res. (2000) [Pubmed]
  11. Molecular characterisation of GTP1, a Saccharomyces cerevisiae gene encoding a small GTP-binding protein. Wolter, R., Richter, D., Niegemann, E., Brendel, M. Curr. Genet. (1994) [Pubmed]
  12. Role of PSO genes in the repair of photoinduced interstrand cross-links and photooxidative damage in the DNA of the yeast Saccharomyces cerevisiae. Henriques, J.A., Brozmanova, J., Brendel, M. J. Photochem. Photobiol. B, Biol. (1997) [Pubmed]
  13. Regulation of SNM1, an inducible Saccharomyces cerevisiae gene required for repair of DNA cross-links. Wolter, R., Siede, W., Brendel, M. Mol. Gen. Genet. (1996) [Pubmed]
  14. Molecular cloning of SNM1, a yeast gene responsible for a specific step in the repair of cross-linked DNA. Haase, E., Riehl, D., Mack, M., Brendel, M. Mol. Gen. Genet. (1989) [Pubmed]
  15. Allelism between pso1-1 and rev3-1 mutants and between pso2-1 and snm1 mutants in Saccharomyces cerevisiae. Cassier-Chauvat, C., Moustacchi, E. Curr. Genet. (1988) [Pubmed]
WikiGenes - Universities