It's good to unwind: how Hel308/HelQ helicases are good for health

Abstract

In every living system the information for maintaining and propagating life is contained within a genome. This ‘book of life’ is written in the language of DNA. For life to exist, access to this is essential in order to replicate and repair genetic information for the benefit of future generations. An important group of molecular motor proteins, the helicases, allows access to this book of life by opening up the DNA double helix and exposing the DNA text of individual strands for replication, transcription, translation and repair. Like all molecular motors, helicases use chemical energy derived from the binding and hydrolysis of nucleotide triphosphates, usually ATP, to carry out mechanical tasks. They come in a variety of structures and employ different mechanisms to carry out diverse mechanical tasks. One large group of helicases are required for repairing DNA that has become damaged by radiation, chemicals or other proteins stuck on the DNA (‘roadblocks’). These DNA repair helicases are also diverse in form and function, having evolved in all forms of life to deal with many different types of DNA damage. However, they have the common property of being able to slide along and unwind DNA molecules to allow DNA repair enzymes access to fix the damage.