New insight into the structure of a virus enzyme that orchestrates a natural type of genetic engineering in bacteria provides important clues into how similar enzymes control the same process in human cells during DNA replication and repair. These findings from investigators at St. Jude Children’s Research Hospital are published in the April issue of Structure. The St. Jude researchers developed a 3-D image of a key part of UvsW, a type of enzyme called a helicase. Helicase enzymes open up the double-stranded DNA molecules like a zipper, so each strand can be replicated to produce two new pieces of DNA. T4, a virus that infects bacteria, uses UvsW during a process called recombinant-dependent replication (RDR). RDR is a type of natural genetic engineering by which viruses, plants and animals introduce new genes into the DNA of one chromosome during replication and repair of broken DNA by using a section of another chromosome as a blueprint. The scientists studied the T4 helicase because it is a simple but effective model for understanding how similar helicases perform the same job in human cells.
