RecQ-like helicases: the DNA replication checkpoint connection

The eukaryotic homologues of the Escherichia coli RecQ DNA helicase play co nserved roles in the maintenance of genome stability. Results obtained in y east and mammalian systems are beginning to form a coherent picture about w hat these helicases do to ensure normal cell division and why humans who la ck these enzymes are cancer prone. Recent data suggest that the yeast enzym e Sgs1p, as well as two human homologues, which are encoded by the Bloom's and Werner's syndrome genes, function during DNA replication and possibly i n a replication checkpoint specific to S phase.