Category Ranking
98%
Total Visits
921
Avg Visit Duration
2 minutes
Citations
20
Article Abstract
Pif1 plays multiple roles in maintaining genome stability and preferentially unwinds forked dsDNA, but the mechanism by which Pif1 unwinds forked dsDNA remains elusive. Here we report the structure of Bacteroides sp Pif1 (BaPif1) in complex with a symmetrical double forked dsDNA. Two interacting BaPif1 molecules are bound to each fork of the partially unwound dsDNA, and interact with the 5' arm and 3' ss/dsDNA respectively. Each of the two BaPif1 molecules is an active helicase and their interaction may regulate their helicase activities. The binding of BaPif1 to the 5' arm causes a sharp bend in the 5' ss/dsDNA junction, consequently breaking the first base-pair. BaPif1 bound to the 3' ss/dsDNA junction impacts duplex unwinding by stabilizing the unpaired first base-pair and engaging the second base-pair poised for breaking. Our results provide an unprecedented insight into how two BaPif1 coordinate with each other to unwind the forked dsDNA.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6879534 | PMC |
| http://dx.doi.org/10.1038/s41467-019-13414-9 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Dissecting the CRISPR Cas1-Cas2 Protospacer Binding and Selection Mechanism by Using Molecular Dynamics Simulations.
J Phys Chem B
April 2024
School of Science, Chongqing University of Posts and Telecommunications, Chongqing 400065, China.
Cas1 and Cas2 are highly conserved proteins among the clustered regularly interspaced short palindromic repeat Cas (CRISPR-Cas) systems and play a crucial role in protospacer selection and integration. According to the double-forked CRISPR Cas1-Cas2 complex, we conducted extensive all-atom molecular dynamics simulations to investigate the protospacer DNA binding and recognition. Our findings revealed that single-point amino acid mutations in Cas1 or in Cas2 had little impact on the binding of the protospacer, both in the binding and precatalytic states.
View Article and Find Full Text PDFStructural basis for DNA unwinding at forked dsDNA by two coordinating Pif1 helicases.
Nat Commun
November 2019
Life Sciences Institute, Zhejiang University, 388 Yuhangtang Road, Hangzhou, 310058, China.
Pif1 plays multiple roles in maintaining genome stability and preferentially unwinds forked dsDNA, but the mechanism by which Pif1 unwinds forked dsDNA remains elusive. Here we report the structure of Bacteroides sp Pif1 (BaPif1) in complex with a symmetrical double forked dsDNA. Two interacting BaPif1 molecules are bound to each fork of the partially unwound dsDNA, and interact with the 5' arm and 3' ss/dsDNA respectively.
View Article and Find Full Text PDFReplication Fork Activation Is Enabled by a Single-Stranded DNA Gate in CMG Helicase.
Cell
July 2019
Laboratory of Nanoscale Biophysics and Biochemistry, The Rockefeller University, New York, NY 10065, USA. Electronic address:
The eukaryotic replicative helicase CMG is a closed ring around double-stranded (ds)DNA at origins yet must transition to single-stranded (ss)DNA for helicase action. CMG must also handle repair intermediates, such as reversed forks that lack ssDNA. Here, using correlative single-molecule fluorescence and force microscopy, we show that CMG harbors a ssDNA gate that enables transitions between ss and dsDNA.
View Article and Find Full Text PDFAsynchrony of Base-Pair Breaking and Nucleotide Releasing of Helicases in DNA Unwinding.
J Phys Chem B
June 2018
Beijing National Laboratory for Condensed Matter Physics, CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190 , China.
Article Synopsis
- Helicases use energy from nucleotide triphosphate hydrolysis to unwind double-stranded DNA (dsDNA) in discrete steps, but how they do this is still not fully understood.
- The study used single-molecule fluorescent resonant energy transfer to analyze the stepping mechanisms of two helicases, E. coli RecQ and ScPif1, revealing they unwind dsDNA in varying step sizes, particularly when tension is applied.
- A proposed universal stepping mechanism suggests helicases break one base pair at a time and hold onto the newly formed nucleotides before releasing them after a random number of breaking events, providing insights into their unwinding patterns.
Gp41, a superfamily SF2 helicase from bacteriophage BFK20.
Virus Res
February 2018
Department of Genomics and Biotechnology, Institute of Molecular Biology, Slovak Academy of Sciences, Dubravska cesta 21, 845 51, Bratislava, Slovakia. Electronic address:
Gp41 is one of two helicases encoded by the genome of bacteriophage BFK20. The gp41 sequence contains conserved motifs from the SF2 family of helicases. We prepared and studied three recombinant proteins: gp41HN, a wild type-like protein with an N-terminal His-Tag; gp41HC, with an S2A mutation and a C-terminal His-Tag; and gp41dC, a mutant protein with a deleted C-terminal region and His-Tags on both N- and C-termini.
View Article and Find Full Text PDF