Grip it and rip it: Structural mechanisms of DNA helicase substrate binding and unwinding

摘要: Maintenance and faithful transmission of genomic information depends on the efficient execution numerous DNA replication, recombination, repair pathways. Many enzymes that catalyze steps within these pathways require access to sequence is buried in interior double helix, which makes unwinding an essential cellular reaction. The process mediated by specialized molecular motors called helicases couple chemical energy derived from nucleoside triphosphate hydrolysis otherwise non-spontaneous An impressive number high-resolution helicase structures are now available that, together with equally important mechanistic studies, have begun define features allow this class function as motors. In review, we explore structural used bind unwind DNA. We focus particular "aromatic-rich loops" some single-stranded binding ATP "wedge/pin" elements provide mechanical tools for strand separation when connected translocating motor domains.