Helicase Mechanisms in Nucleic Acid Processing

Helicases are specialised motor proteins that harness the energy of ATP hydrolysis to unwind and translocate along nucleic acid duplexes, thereby facilitating critical processes such as DNA replication, repair, recombination and RNA splicing. They typically comprise conserved RecA‐like domains that undergo coordinated conformational changes, advancing in stepwise motions often described by inchworm or caterpillar‐like models. In the context of replication, hexameric helicases form the core of the replisome, encircling one strand of DNA and separating the duplex ahead of the polymerase; accessory monomeric helicases may bind transiently to remove protein‐bound obstacles. During repair and recombination, helicases remodel complex nucleoprotein structures, regress stalled forks or resolve displacement loops. Single‐molecule and high‐resolution structural studies have revealed how domain motions, mediated by release of arginine fingers or hook‐loop motifs, control strand separation and directional translocation. Beyond fundamental cell biology, engineered light‐responsive helicases and opto-helicase variants promise applications in synthetic biology, spatial control of hybridisation and targeted genome manipulation. Malfunctions in helicase activity underlie genomic instability disorders, emphasising their global and medical significance.

Research from Nature Portfolio

Recent studies have elucidated the multi‐faceted roles of helicase‐like ATPases in nucleic acid processing. One investigation combined ultrafast twist measurements with fluorescence assays to reveal that a restriction–modification enzyme’s helicase‐like domain not only stabilises initial DNA interactions but also triggers conformational changes in flipped bases and drives constrained translocation of small double‐stranded loops. This work unifies previously conflicting models of long‐range DNA sliding and site communication. Another report achieved an atomic‐scale reconstruction of RNA translocation by a DEAH‐box helicase using enhanced sampling molecular dynamics. It demonstrated that large‐scale domain motions follow an inchworm/caterpillar hybrid mechanism, requiring a sequence of local atomic‐scale transitions—release of an arginine finger, stepping of hook‐loop and hook‐turn motifs—to achieve processive movement. These findings advance understanding of the coupling between ATPase chemistry and mechanical work in RNA splicing enzymes.

Helicase Mechanisms in Nucleic Acid Processing publication trend

The graph below shows the total number of articles in helicase mechanisms in nucleic acid processing across all publications each year (not limited to Nature Index journals).

Technical terms

Helicase: An enzyme that couples ATP hydrolysis to directional unwinding of double-stranded nucleic acids.

ATP hydrolysis: The enzymatic conversion of ATP to ADP and inorganic phosphate, releasing free energy used to power mechanochemical movements.

RecA‐like domain: A conserved structural module within helicases that binds ATP and undergoes conformational changes to translocate along nucleic acid.

Nucleic acid translocation: The process by which a protein moves directionally along DNA or RNA without necessarily unwinding it.

Conformational cycle: A sequence of structural rearrangements in a protein, driven by ligand binding and hydrolysis, that result in mechanical work.

References

1. Recipient UvrD helicase is involved in single- to double-stranded DNA conversion during conjugative plasmid transfer. Nucleic Acids Research (2023).
2. Helicase Activity Modulation with On-Demand Light-Based Conformational Control. Journal of the American Chemical Society (2023).
3. Short-range translocation by a restriction enzyme motor triggers diffusion along DNA. Nature Chemical Biology (2024).
4. Continuous millisecond conformational cycle of a DEAH box helicase reveals control of domain motions by atomic-scale transitions. Communications Biology (2023).
5. Sequence-dependent base pair stepping dynamics in XPD helicase unwinding. eLife (2013).