Abstract
Homologous recombination and double-stranded DNA break repair in Escherichia coli are initiated by the multifunctional RecBCD enzyme. After binding to a double-stranded DNA end, the RecBCD enzyme unwinds and degrades the DNA processively. This processing is regulated by the recombination hot spot, Chi (χ: 5'-GCTGGTGG-3'), which induces a switch in the polarity of DNA degradation and activates RecBCD enzyme to coordinate the loading of the DNA strand exchange protein, RecA, onto the single-stranded DNA products of unwinding. Recently, a single mutation in RecB, Asp-1080 → Ala, was shown to create an enzyme (RecB(D1080A)CD) that is a processive helicase but not a nuclease. Here we show that the RecB(D1080A)CD enzyme is also unable to coordinate the loading of the RecA protein, regardless of whether χ sites are present in the DNA. However, the RecB(D1080A)CD enzyme does respond to χ sites by inactivating in a χ-dependent manner. These data define a locus of the RecBCD enzyme that is essential not only for nuclease function but also for the coordination of RecA protein loading.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 27139-27144 |
| Number of pages | 6 |
| Journal | Journal of Biological Chemistry |
| Volume | 274 |
| Issue number | 38 |
| DOIs | |
| State | Published - Sep 17 1999 |
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ASJC Scopus subject areas
- Biochemistry
Cite this
A single mutation, RecB(D1080A), eliminates RecA protein loading but not Chi recognition by RecBCD enzyme. / Anderson, Daniel G.; Churchill, Jason J.; Kowalczykowski, Stephen C.
In: Journal of Biological Chemistry, Vol. 274, No. 38, 17.09.1999, p. 27139-27144.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - A single mutation, RecB(D1080A), eliminates RecA protein loading but not Chi recognition by RecBCD enzyme
AU - Anderson, Daniel G.
AU - Churchill, Jason J.
AU - Kowalczykowski, Stephen C.
PY - 1999/9/17
Y1 - 1999/9/17
N2 - Homologous recombination and double-stranded DNA break repair in Escherichia coli are initiated by the multifunctional RecBCD enzyme. After binding to a double-stranded DNA end, the RecBCD enzyme unwinds and degrades the DNA processively. This processing is regulated by the recombination hot spot, Chi (χ: 5'-GCTGGTGG-3'), which induces a switch in the polarity of DNA degradation and activates RecBCD enzyme to coordinate the loading of the DNA strand exchange protein, RecA, onto the single-stranded DNA products of unwinding. Recently, a single mutation in RecB, Asp-1080 → Ala, was shown to create an enzyme (RecB(D1080A)CD) that is a processive helicase but not a nuclease. Here we show that the RecB(D1080A)CD enzyme is also unable to coordinate the loading of the RecA protein, regardless of whether χ sites are present in the DNA. However, the RecB(D1080A)CD enzyme does respond to χ sites by inactivating in a χ-dependent manner. These data define a locus of the RecBCD enzyme that is essential not only for nuclease function but also for the coordination of RecA protein loading.
AB - Homologous recombination and double-stranded DNA break repair in Escherichia coli are initiated by the multifunctional RecBCD enzyme. After binding to a double-stranded DNA end, the RecBCD enzyme unwinds and degrades the DNA processively. This processing is regulated by the recombination hot spot, Chi (χ: 5'-GCTGGTGG-3'), which induces a switch in the polarity of DNA degradation and activates RecBCD enzyme to coordinate the loading of the DNA strand exchange protein, RecA, onto the single-stranded DNA products of unwinding. Recently, a single mutation in RecB, Asp-1080 → Ala, was shown to create an enzyme (RecB(D1080A)CD) that is a processive helicase but not a nuclease. Here we show that the RecB(D1080A)CD enzyme is also unable to coordinate the loading of the RecA protein, regardless of whether χ sites are present in the DNA. However, the RecB(D1080A)CD enzyme does respond to χ sites by inactivating in a χ-dependent manner. These data define a locus of the RecBCD enzyme that is essential not only for nuclease function but also for the coordination of RecA protein loading.
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UR - http://www.scopus.com/inward/citedby.url?scp=0033578824&partnerID=8YFLogxK
U2 - 10.1074/jbc.274.38.27139
DO - 10.1074/jbc.274.38.27139
M3 - Article
C2 - 10480929
AN - SCOPUS:0033578824
VL - 274
SP - 27139
EP - 27144
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 38
ER -