A new optical tweezers assay sheds light on the mechanism of cooperation and force generation by the subunits of RecBCD, critical for the repair of double strand breaks in bacteria.

hRPA permits the BLM helicase to bidirectionally unwind DNA from a nick which could potentially facilitate its function switching in DNA repair and promote end resection in homologous recombination.

The rate of DNA unwinding by RecQ helicases is dramatically modulated by the DNA duplex stability in a geometry-dependent manner, providing an intrinsic mechanism for suppressing illegitimate recombination.

The archaeal MCM helicase can load in multiple orientations on DNA but translocation proceeds with a leading N-terminal domain, which affects double hexamer activation at origins of replication.

The CMG complex, the replicative helicase in eukaryotes, uses a different mechanism from bacterial and viral helicases by engaging both strands of parental DNA with substantial force and unwinding the duplex within the central channel of CMG.

The nuclease of hDNA2 limits its processive DNA unwinding capacity; the helicase function becomes stimulatory when hDNA2 is in complex with BLM or WRN helicase to degrade dsDNA.

The crystal structure of Pur-alpha in complex with DNA reveals its molecular mechanisms of nucleic-acid binding and unwinding, allowing for a better understanding of its essential role in neurons.

Analysis of an essential motif in Mcm4 provides insights into replicative helicase double-hexamer formation and the first step requiring this intermediate during replication initiation.

Single-molecule fluorescence experiments reveal transcription initiation proceeds via a 'bind-unwind-load-and-lock' mechanism where promoter DNA unwinds outside the RNA polymerase (RNAP) cleft, the unwound template-DNA loads into the cleft, and RNAP 'locks' the template-DNA by closing the RNAP clamp module.

A detailed model of the T7 replisome with the precise positions of the helicase and polymerase at the replication fork explains how catalysis by the two enzymes is coordinated.