TY - JOUR
T1 - Facilitated loading of RecA protein is essential to recombination by RecBCD enzyme
AU - Arnold, Deana A.
AU - Kowalczykowski, Stephen C.
PY - 2000/4/21
Y1 - 2000/4/21
N2 - Although the RecB2109CD enzyme retains most of the biochemical functions associated with the wild-type RecBCD enzyme, it is completely defective for genetic recombination. Here, we demonstrate that the mutant enzyme exhibits an aberrant double-stranded DNA exonuclease activity, intrinsically producing a 3'-terminal single-stranded DNA overhang that is an ideal substrate for RecA protein-promoted strand invasion. Thus, the mutant enzyme constitutively processes double-stranded DNA in the same manner as the x-modified wild-type RecBCD enzyme. However, we further show that the RecB2109CD enzyme is unable to coordinate the loading of RecA protein onto the single-stranded DNA produced, and we conclude that this inability results in the recombination-defective phenotype of the recB2109 allele. Our findings argue that the facilitated loading of RecA protein by the x- activated RecBCD enzyme is essential for RecBCD-mediated homologous recombination in vivo.
AB - Although the RecB2109CD enzyme retains most of the biochemical functions associated with the wild-type RecBCD enzyme, it is completely defective for genetic recombination. Here, we demonstrate that the mutant enzyme exhibits an aberrant double-stranded DNA exonuclease activity, intrinsically producing a 3'-terminal single-stranded DNA overhang that is an ideal substrate for RecA protein-promoted strand invasion. Thus, the mutant enzyme constitutively processes double-stranded DNA in the same manner as the x-modified wild-type RecBCD enzyme. However, we further show that the RecB2109CD enzyme is unable to coordinate the loading of RecA protein onto the single-stranded DNA produced, and we conclude that this inability results in the recombination-defective phenotype of the recB2109 allele. Our findings argue that the facilitated loading of RecA protein by the x- activated RecBCD enzyme is essential for RecBCD-mediated homologous recombination in vivo.
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U2 - 10.1074/jbc.275.16.12261
DO - 10.1074/jbc.275.16.12261
M3 - Article
C2 - 10766864
AN - SCOPUS:0034697325
VL - 275
SP - 12261
EP - 12265
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 16
ER -