| Modification Notes |
Fob1 is a 566 amino acid protein encoded by the yeast gene FOB1. DNA damage can result in a replication block that stalls replication forks. The recovery of such stalled replication forks plays a crucial role in the genomic maintenance. A pause in DNA replication can also promote double-strand breaks and mitotic recombination. In Saccharomyces cerevisiae, the ribosomal DNA (rDNA) locus serves as a model to study all stages of DNA replication. Yeast cells carry approximately 150 rDNA copies in tandem repeats, with each repeat consisting of the 35S rRNA gene, the NTS1 spacer, the 5S rRNA gene and the NTS2 spacer. Fob1 (fork blocking less) regulates replication fork block (RFB) activity at the RFB site in NTS1, recombination hot spot activity and rDNA repeat expansion and contraction. Mutations in the Fob1 gene slow production of circular species of rDNA produced by the tandem repeats, which extends the life span of yeast cells. |