Open AccessAntipairing and strand transferase activities ofE.colihelicase II (UvrD)
Author(s) -
Patrice Morel,
James Hejna,
S. Dusko Ehrlich,
Era Cassuto
Publication year - 1993
Publication title -
nucleic acids research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.008
H-Index - 537
eISSN - 1362-4954
pISSN - 0305-1048
DOI - 10.1093/nar/21.14.3205
Subject(s) - biology , helicase , homologous recombination , transposable element , dna repair , escherichia coli , genetics , dna mismatch repair , homologous chromosome , mutant , gene , microbiology and biotechnology , rna
The product of the uvrD gene of Escherichia coli, UvrD (helicase II), is known to be involved in methyl-directed mismatch repair, transposon excision and uvrABC excision repair. In conjugational crosses, various uvrD mutants have been reported to result in higher, lower or unaffected recombination frequencies. In an attempt to clarify the role of UvrD in recombination, we have studied in vitro its effects on two key reactions driven by RecA, homologous pairing and strand exchange. We show here that UvrD efficiently prevents or reverses RecA-mediated homologous pairing. Unexpectedly, we also found that it can stimulate RecA-driven branch migration and even catalyze strand exchange in the absence of RecA. A possible in vivo role for these antagonistic activities is discussed.