RecQ DNA helicase is a suppressor of illegitimate recombination in Escherichia coli
- 15 April 1997
- journal article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 94 (8), 3860-3865
- https://doi.org/10.1073/pnas.94.8.3860
Abstract
Bloom syndrome and Werner syndrome are genetic disorders in which an increased rate of chromosomal abnormality is observed. The genes responsible for these diseases, BLM and WRN, have been cloned and identified as homologs of the Escherichia coli recQ genes. We studied the effect of recQ mutations on illegitimate recombination, which is an aberrant biological event related to the chromosomal abnormality in humans, and found that a variety of recQ mutations increased spontaneous illegitimate recombination by 20- to 300-fold and increased UV light-induced illegitimate recombination by 10- to 100-fold. Most lambda bio or lambda pro transducing phages are formed by the recombination events at several hot spots, which are enhanced by the recQ mutation. The analysis of nucleotide sequences at the recombination junction in the transducing phages indicates that recombination at the hot spot sites as well as the non-hot spot sites takes place between short homologous sequences. Enhancement of the recombination in the recQ mutants also occurs in the recA, recBC sbcBC, or recBC sbcA backgrounds, indicating that these recombination events are mediated by none of the known recombination pathways, RecBC, RecF, and RecE. We therefore concluded that the RecQ function suppresses illegitimate recombination that depends on short homologous regions. We discuss a model, based on the 3'-to-5' helicase activity of RecQ, to explain the role of this protein as a suppressor of illegitimate recombination.Keywords
This publication has 28 references indexed in Scilit:
- Short-homology-independent illegitimate recombination in Escherichia coli: distinct mechanism from short-homology-dependent illegitimate recombinationJournal of Molecular Biology, 1997
- Positional Cloning of the Werner's Syndrome GeneScience, 1996
- Construction of mini-F plasmid vectors for plasmid shuffling in Escherichia coliGene, 1996
- The Bloom's syndrome gene product is homologous to RecQ helicasesCell, 1995
- A novel assay for illegitimate recombination in Escherichia coli: Stimulation of ?bio transducing phage formation by ultra-violet light and its independence from RecA functionAdvances in Biophysics, 1995
- Nucleotide sequence analysis of human hypoxanthine phosphoribosyltransferase (HPRT) gene deletionsGenomics, 1992
- The recQ gene of Escherichia coli K12: primary structure and evidence for SOS regulationMolecular Genetics and Genomics, 1986
- The recQ gene of Escherichia coli K12: molecular cloning and isolation of insertion mutantsMolecular Genetics and Genomics, 1985
- Isolation and genetic characterization of a thymineless death-resistant mutant of Escherichia coli K12: Identification of a new mutation (recQ1) that blocks the RecF recombination pathwayMolecular Genetics and Genomics, 1984
- Genetic analysis of the recF pathway to genetic recombination in Escherichia coli k12: Isolation and characterization of mutantsJournal of Molecular Biology, 1973