title: Localization of RecA in Escherichia coli K-12 using RecA-GFP.
abstract: RecA is important in recombination, DNA repair and repair of replication forks. It functions through the production of a protein-DNA filament. To study the localization of RecA in live Escherichia coli cells, the RecA protein was fused to the green fluorescence protein (GFP). Strains with this gene have recombination/DNA repair activities three- to tenfold below wild type (or about 1000-fold above that of a recA null mutant). RecA-GFP cells have a background of green fluorescence punctuated with up to five foci per cell. Two types of foci have been defined: 4,6-diamidino-2-phenylindole (DAPI)-sensitive foci that are bound to DNA and DAPI-insensitive foci that are DNA-less aggregates/storage structures. In log phase cells, foci were not localized to any particular region. After UV irradiation, the number of foci increased and they localized to the cell centre. This suggested colocalization with the DNA replication factory. recA, recB and recF strains showed phenotypes and distributions of foci consistent with the predicted effects of these mutations.
authors.affiliation: Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, USA.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Renzette
authors.forename: Nathan
authors.initials: N
authors.lastname: Gumlaw
authors.forename: Jared T
authors.initials: JT
authors.lastname: Nordman
authors.forename: Marlee
authors.initials: M
authors.lastname: Krieger
authors.forename: Su-Ping
authors.initials: SP
authors.lastname: Yeh
authors.forename: Edward
authors.initials: E
authors.lastname: Long
authors.forename: Richard
authors.initials: R
authors.lastname: Centore
authors.forename: Ruethairat
authors.initials: R
authors.lastname: Boonsombat
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Sandler
mesh_terms: D002876:Chromosomes, Bacterial / Q000378:metabolism; D004261:DNA Replication; D004269:DNA, Bacterial / Q000378:metabolism / Q000528:radiation effects; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000528:radiation effects; D029968:Escherichia coli Proteins / Q000032:analysis* / Q000235:genetics; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000235:genetics; D009154:Mutation; D011938:Rec A Recombinases / Q000032:analysis* / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000032:analysis / Q000235:genetics; D011995:Recombination, Genetic; D014466:Ultraviolet Rays
chemical_list: D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D011938:Rec A Recombinases