Abstract
The unwinding and priming activities of the bacteriophage T4 primosome, which consists of a hexameric helicase (gp41) translocating 5′ to 3′ and an oligomeric primase (gp61) synthesizing primers 5′ to 3′ have been investigated on DNA hairpins manipulated by a magnetic trap. We find that the T4 primosome continuously unwinds the DNA duplex while allowing for primer synthesis through a primosome disassembly mechanism or a new DNA looping mechanism. A fused gp61-gp41 primosome unwinds and primes DNA exclusively via the DNA looping mechanism. Other proteins within the replisome control the partitioning of these two mechanisms by disfavoring primosome disassembly, thereby increasing primase processivity. In contrast to T4, priming in bacteriophage T7 and Escherichia coli involves discrete pausing of the primosome and dissociation of the primase from the helicase, respectively. Thus nature appears to use several strategies to couple the disparate helicase and primase activities within primosomes.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 904-912 |
| Number of pages | 9 |
| Journal | Nature Chemical Biology |
| Volume | 5 |
| Issue number | 12 |
| DOIs | |
| State | Published - Dec 2009 |
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All Science Journal Classification (ASJC) codes
- Molecular Biology
- Cell Biology
Cite this
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Coupling DNA unwinding activity with primer synthesis in the bacteriophage T4 primosome. / Manosas, Maria; Spiering, Michelle M.; Zhuang, Zhihao; Benkovic, Stephen J.; Croquette, Vincent.
In: Nature Chemical Biology, Vol. 5, No. 12, 12.2009, p. 904-912.Research output: Contribution to journal › Article
TY - JOUR
T1 - Coupling DNA unwinding activity with primer synthesis in the bacteriophage T4 primosome
AU - Manosas, Maria
AU - Spiering, Michelle M.
AU - Zhuang, Zhihao
AU - Benkovic, Stephen J.
AU - Croquette, Vincent
PY - 2009/12
Y1 - 2009/12
N2 - The unwinding and priming activities of the bacteriophage T4 primosome, which consists of a hexameric helicase (gp41) translocating 5′ to 3′ and an oligomeric primase (gp61) synthesizing primers 5′ to 3′ have been investigated on DNA hairpins manipulated by a magnetic trap. We find that the T4 primosome continuously unwinds the DNA duplex while allowing for primer synthesis through a primosome disassembly mechanism or a new DNA looping mechanism. A fused gp61-gp41 primosome unwinds and primes DNA exclusively via the DNA looping mechanism. Other proteins within the replisome control the partitioning of these two mechanisms by disfavoring primosome disassembly, thereby increasing primase processivity. In contrast to T4, priming in bacteriophage T7 and Escherichia coli involves discrete pausing of the primosome and dissociation of the primase from the helicase, respectively. Thus nature appears to use several strategies to couple the disparate helicase and primase activities within primosomes.
AB - The unwinding and priming activities of the bacteriophage T4 primosome, which consists of a hexameric helicase (gp41) translocating 5′ to 3′ and an oligomeric primase (gp61) synthesizing primers 5′ to 3′ have been investigated on DNA hairpins manipulated by a magnetic trap. We find that the T4 primosome continuously unwinds the DNA duplex while allowing for primer synthesis through a primosome disassembly mechanism or a new DNA looping mechanism. A fused gp61-gp41 primosome unwinds and primes DNA exclusively via the DNA looping mechanism. Other proteins within the replisome control the partitioning of these two mechanisms by disfavoring primosome disassembly, thereby increasing primase processivity. In contrast to T4, priming in bacteriophage T7 and Escherichia coli involves discrete pausing of the primosome and dissociation of the primase from the helicase, respectively. Thus nature appears to use several strategies to couple the disparate helicase and primase activities within primosomes.
UR - http://www.scopus.com/inward/record.url?scp=72449179248&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=72449179248&partnerID=8YFLogxK
U2 - 10.1038/nchembio.236
DO - 10.1038/nchembio.236
M3 - Article
C2 - 19838204
AN - SCOPUS:72449179248
VL - 5
SP - 904
EP - 912
JO - Nature Chemical Biology
JF - Nature Chemical Biology
SN - 1552-4450
IS - 12
ER -