Abstract
The AddAB enzyme is important to homologous DNA recombination in Bacillus subtilis, where it is thought to be the functional counterpart of the RecBCD enzyme of Escherichi a coli. In vivo, AddAB responds to a specific five-nucleotide sequence (5'-AGCGG-3' or its complement) in a manner analogous to the response of the RecBCD enzyme to interaction with χ sequences. Here, we show that purified AddAB enzyme is able to load at a double-stranded DNA end and is both a DNA helicase and nuclease, whose combined action results in the degradation of both strands of the DNA duplex. During translocation, recognition of the properly oriented sequence 5'-AGCGG-3' causes attenuation of the AddAB enzyme nuclease activity that is responsible for degradation of the strand 3'-terminal at the entry site. Therefore, we conclude that 5'-AGCGG-3' is the B. subtilis Chi site and it is hereafter referred to as χ(Bs). After encountering χ(Bs), both the degradation of the 5'-terminal strand and the helicase activity persist. Thus, processing of a double-stranded DNA end by the AddAB enzyme produces a duplex DNA molecule with a protruding 3'-terminated single-stranded tail, a universal intermediate of the recombination process. (C) 2000 Academic Press.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 7-20 |
| Number of pages | 14 |
| Journal | Journal of Molecular Biology |
| Volume | 298 |
| Issue number | 1 |
| DOIs | |
| State | Published - Apr 21 2000 |
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Keywords
- AddAB
- Chi
- Helicase
- Homologous recombination
- Nuclease
ASJC Scopus subject areas
- Virology
Cite this
The Bacillus subtilis AddAB helicase/nuclease is regulated by its cognate Chi sequence in vitro. / Chedin, Frederic; Ehrlich, S. Dusko; Kowalczykowski, Stephen C.
In: Journal of Molecular Biology, Vol. 298, No. 1, 21.04.2000, p. 7-20.Research output: Contribution to journal › Article
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TY - JOUR
T1 - The Bacillus subtilis AddAB helicase/nuclease is regulated by its cognate Chi sequence in vitro
AU - Chedin, Frederic
AU - Ehrlich, S. Dusko
AU - Kowalczykowski, Stephen C.
PY - 2000/4/21
Y1 - 2000/4/21
N2 - The AddAB enzyme is important to homologous DNA recombination in Bacillus subtilis, where it is thought to be the functional counterpart of the RecBCD enzyme of Escherichi a coli. In vivo, AddAB responds to a specific five-nucleotide sequence (5'-AGCGG-3' or its complement) in a manner analogous to the response of the RecBCD enzyme to interaction with χ sequences. Here, we show that purified AddAB enzyme is able to load at a double-stranded DNA end and is both a DNA helicase and nuclease, whose combined action results in the degradation of both strands of the DNA duplex. During translocation, recognition of the properly oriented sequence 5'-AGCGG-3' causes attenuation of the AddAB enzyme nuclease activity that is responsible for degradation of the strand 3'-terminal at the entry site. Therefore, we conclude that 5'-AGCGG-3' is the B. subtilis Chi site and it is hereafter referred to as χ(Bs). After encountering χ(Bs), both the degradation of the 5'-terminal strand and the helicase activity persist. Thus, processing of a double-stranded DNA end by the AddAB enzyme produces a duplex DNA molecule with a protruding 3'-terminated single-stranded tail, a universal intermediate of the recombination process. (C) 2000 Academic Press.
AB - The AddAB enzyme is important to homologous DNA recombination in Bacillus subtilis, where it is thought to be the functional counterpart of the RecBCD enzyme of Escherichi a coli. In vivo, AddAB responds to a specific five-nucleotide sequence (5'-AGCGG-3' or its complement) in a manner analogous to the response of the RecBCD enzyme to interaction with χ sequences. Here, we show that purified AddAB enzyme is able to load at a double-stranded DNA end and is both a DNA helicase and nuclease, whose combined action results in the degradation of both strands of the DNA duplex. During translocation, recognition of the properly oriented sequence 5'-AGCGG-3' causes attenuation of the AddAB enzyme nuclease activity that is responsible for degradation of the strand 3'-terminal at the entry site. Therefore, we conclude that 5'-AGCGG-3' is the B. subtilis Chi site and it is hereafter referred to as χ(Bs). After encountering χ(Bs), both the degradation of the 5'-terminal strand and the helicase activity persist. Thus, processing of a double-stranded DNA end by the AddAB enzyme produces a duplex DNA molecule with a protruding 3'-terminated single-stranded tail, a universal intermediate of the recombination process. (C) 2000 Academic Press.
KW - AddAB
KW - Chi
KW - Helicase
KW - Homologous recombination
KW - Nuclease
UR - http://www.scopus.com/inward/record.url?scp=0034696750&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0034696750&partnerID=8YFLogxK
U2 - 10.1006/jmbi.2000.3556
DO - 10.1006/jmbi.2000.3556
M3 - Article
VL - 298
SP - 7
EP - 20
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
SN - 0022-2836
IS - 1
ER -