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Mechanisms of hexameric helicases
Amy J Fernandez1, James M Berger1
1Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD, USA.
Critical Reviews in Biochemistry and Molecular Biology
|August 18, 2021
Summary
Ring-shaped hexameric helicases unwind DNA and RNA using NTP hydrolysis. Recent studies reveal shared mechanisms across diverse helicase families, advancing our understanding of these essential motor proteins.
Area of Science:
- Biochemistry
- Molecular Biology
- Structural Biology
Background:
- Ring-shaped hexameric helicases are crucial motor proteins involved in DNA replication, recombination, and transcriptional regulation.
- Two main lineages, based on RecA and AAA+ ATPase folds, have been identified.
Purpose of the Study:
- To review recent structural and biophysical findings on hexameric helicase mechanisms.
- To highlight commonalities in NTP hydrolysis and substrate translocation across different helicase families.
- To identify outstanding questions regarding their function.
Main Methods:
- Literature review of recent structural and biophysical studies.
- Analysis of molecular mechanisms of NTP hydrolysis and substrate translocation.
- Comparative analysis of diverse hexameric helicase families.
Main Results:
- Emerging evidence reveals conserved mechanisms in NTP hydrolysis and substrate translocation among various hexameric helicases.
- Conformational changes coupled to NTP hydrolysis drive nucleic acid translocation through the central pore.
- Commonalities in how these enzymes engage and process nucleic acid substrates are becoming apparent.
Conclusions:
- Hexameric helicases share fundamental mechanisms for NTP hydrolysis and nucleic acid translocation, despite evolutionary diversity.
- Further research is needed to fully elucidate the intricacies of their function and substrate engagement.
- Understanding these conserved mechanisms is key to comprehending DNA replication, repair, and gene expression.
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