A radical solution to death

The Saccharomyces cerevisiae gene SGS1 encodes a protein related to the hum an DNA helicases defective in Werner syndrome, Bloom syndrome and Rothmund- Thomson syndrome. Yeast cells lacking the Sgs1 helicase and a related helic ase. Srs2. are inviable or grow extremely poorly. The growth defect can be rescued by crippling the homologous recombination repair pathway, indicatin g that the essential function of these genes is related to recombination.