NUCLEOTIDE EXCISION-REPAIR IN THE YEAST SACCHAROMYCES-CEREVISIAE - ITS RELATIONSHIP TO SPECIALIZED MITOTIC RECOMBINATION AND RNA-POLYMERASE-II BASAL TRANSCRIPTION

Nucleotide excision repair (NER) in eukaryotes is a biochemically comp lex process involving multiple gene products. The budding yeast Saccha romyces cerevisiae is an informative model for this process. Multiple genes and in some cases gene products that are indispensable for NER h ave been isolated from this organism. Homologues of many of these yeas t genes are structurally and functionally conserved in higher organism s, including humans. The yeast Rad1/Rad10 heterodimeric protein comple x is an endonuclease that is believed to participate in damage-specifi c incision of DNA during NER. This endonuclease is also required for s pecialized types of recombination. The products of the RAD3, SSL2(RAD2 5) SSL1 and TFB1 genes have dual roles in NER and in RNA polymerase II -dependent basal transcription.