Periodic DNA patrolling underlies diverse functions of Pif1 on R-loops and G-rich DNA
Pif1 family helicases are conserved from bacteria to humans. Here, we report a novel DNA patrolling activity which may underlie Pif1’s diverse functions: a Pif1 monomer preferentially anchors itself to a 3′-tailed DNA junction and periodically reel in the 3′ tail with a step size of one nucleotide,...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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eLife Sciences Publications Ltd
2014-04-01
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| Series: | eLife |
| Subjects: | |
| Online Access: | https://elifesciences.org/articles/02190 |
| _version_ | 1818018936217665536 |
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| author | Ruobo Zhou Jichuan Zhang Matthew L Bochman Virginia A Zakian Taekjip Ha |
| author_facet | Ruobo Zhou Jichuan Zhang Matthew L Bochman Virginia A Zakian Taekjip Ha |
| author_sort | Ruobo Zhou |
| collection | DOAJ |
| description | Pif1 family helicases are conserved from bacteria to humans. Here, we report a novel DNA patrolling activity which may underlie Pif1’s diverse functions: a Pif1 monomer preferentially anchors itself to a 3′-tailed DNA junction and periodically reel in the 3′ tail with a step size of one nucleotide, extruding a loop. This periodic patrolling activity is used to unfold an intramolecular G-quadruplex (G4) structure on every encounter, and is sufficient to unwind RNA-DNA heteroduplex but not duplex DNA. Instead of leaving after G4 unwinding, allowing it to refold, or going beyond to unwind duplex DNA, Pif1 repeatedly unwinds G4 DNA, keeping it unfolded. Pif1-induced unfolding of G4 occurs in three discrete steps, one strand at a time, and is powerful enough to overcome G4-stabilizing drugs. The periodic patrolling activity may keep Pif1 at its site of in vivo action in displacing telomerase, resolving R-loops, and keeping G4 unfolded during replication, recombination and repair. |
| first_indexed | 2024-04-14T07:46:08Z |
| format | Article |
| id | doaj.art-7fecf9deb62244bd975fd4fd30a85529 |
| institution | Directory Open Access Journal |
| issn | 2050-084X |
| language | English |
| last_indexed | 2024-04-14T07:46:08Z |
| publishDate | 2014-04-01 |
| publisher | eLife Sciences Publications Ltd |
| record_format | Article |
| series | eLife |
| spelling | doaj.art-7fecf9deb62244bd975fd4fd30a855292022-12-22T02:05:20ZengeLife Sciences Publications LtdeLife2050-084X2014-04-01310.7554/eLife.02190Periodic DNA patrolling underlies diverse functions of Pif1 on R-loops and G-rich DNARuobo Zhou0Jichuan Zhang1Matthew L Bochman2Virginia A Zakian3Taekjip Ha4Center for the Physics of Living Cells, Department of Physics, University of Illinois at Urbana-Champaign, Urbana, United StatesCenter for the Physics of Living Cells, Department of Physics, University of Illinois at Urbana-Champaign, Urbana, United States; Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, United StatesDepartment of Molecular Biology, Princeton University, Princeton, United StatesDepartment of Molecular Biology, Princeton University, Princeton, United StatesCenter for the Physics of Living Cells, Department of Physics, University of Illinois at Urbana-Champaign, Urbana, United States; Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, Urbana, United StatesPif1 family helicases are conserved from bacteria to humans. Here, we report a novel DNA patrolling activity which may underlie Pif1’s diverse functions: a Pif1 monomer preferentially anchors itself to a 3′-tailed DNA junction and periodically reel in the 3′ tail with a step size of one nucleotide, extruding a loop. This periodic patrolling activity is used to unfold an intramolecular G-quadruplex (G4) structure on every encounter, and is sufficient to unwind RNA-DNA heteroduplex but not duplex DNA. Instead of leaving after G4 unwinding, allowing it to refold, or going beyond to unwind duplex DNA, Pif1 repeatedly unwinds G4 DNA, keeping it unfolded. Pif1-induced unfolding of G4 occurs in three discrete steps, one strand at a time, and is powerful enough to overcome G4-stabilizing drugs. The periodic patrolling activity may keep Pif1 at its site of in vivo action in displacing telomerase, resolving R-loops, and keeping G4 unfolded during replication, recombination and repair.https://elifesciences.org/articles/02190Pif1 family helicasesingle molecule analysisG-quadruplexesR-loop |
| spellingShingle | Ruobo Zhou Jichuan Zhang Matthew L Bochman Virginia A Zakian Taekjip Ha Periodic DNA patrolling underlies diverse functions of Pif1 on R-loops and G-rich DNA eLife Pif1 family helicase single molecule analysis G-quadruplexes R-loop |
| title | Periodic DNA patrolling underlies diverse functions of Pif1 on R-loops and G-rich DNA |
| title_full | Periodic DNA patrolling underlies diverse functions of Pif1 on R-loops and G-rich DNA |
| title_fullStr | Periodic DNA patrolling underlies diverse functions of Pif1 on R-loops and G-rich DNA |
| title_full_unstemmed | Periodic DNA patrolling underlies diverse functions of Pif1 on R-loops and G-rich DNA |
| title_short | Periodic DNA patrolling underlies diverse functions of Pif1 on R-loops and G-rich DNA |
| title_sort | periodic dna patrolling underlies diverse functions of pif1 on r loops and g rich dna |
| topic | Pif1 family helicase single molecule analysis G-quadruplexes R-loop |
| url | https://elifesciences.org/articles/02190 |
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