Mechanisms of helicase-catalyzed DNA unwinding

Timothy M. Lohman, Keith P. Bjornson

Research output: Contribution to journalReview articlepeer-review

684 Scopus citations


DNA helicases are essential motor proteins that function to unwind duplex DNA to yield the transient single-stranded DNA intermediates required for replication, recombination, and repair. These enzymes unwind duplex DNA and translocate along DNA in reactions that are coupled to the binding and hydrolysis of 5'-nucleoside triphosphates (NTP). Although these enzymes are essential for DNA metabolism, the molecular details of their mechanisms are only beginning to emerge. This review discusses mechanistic aspects of helicase-catalyzed DNA unwinding and translocation with a focus on energetic (thermodynamic), kinetic, and structural studies of the few DNA helicases for which such information is available. Recent studies of DNA and NTP binding and DNA unwinding by the Escherichia coli (E. coli) Rep helicase suggest that the Rep helicase dimer unwinds DNA by an active, rolling mechanism. In fact, DNA helicases appear to be generally oligomeric (usually dimers or hexamers), which provides the helicase with multiple DNA binding sites. The apparent mechanistic similarities and differences among these DNA helicases are discussed.

Original languageEnglish
Pages (from-to)169-214
Number of pages46
JournalAnnual review of biochemistry
StatePublished - 1996


  • DNA-protein interactions
  • allosterism
  • energy transduction
  • kinetics
  • mechanism
  • motor proteins
  • replication


Dive into the research topics of 'Mechanisms of helicase-catalyzed DNA unwinding'. Together they form a unique fingerprint.

Cite this