title: Marker-dependent recombination in T4 bacteriophage. IV. Recombinational effects of antimutator T4 DNA polymerase.
abstract: Recombinational effects of the antimutator allele tsL42 of gene 43 of phage T4, encoding DNA polymerase, were studied in crosses between rIIB mutants. Recombination under tsL42-restricted conditions differed from the normal one in several respects: (1) basic recombination was enhanced, especially within very short distances; (2) mismatch repair tracts were shortened, while the contribution of mismatch repair to recombination was not changed; (3) marker interference at very short distances was augmented. We infer that the T4 DNA polymerase is directly involved in mismatch repair, performing both excision of a nonmatched single strand (by its 3'-->5' exonuclease) and filling the resulting gap. A pathway for the mismatch repair was substantiated; it includes sequential action of endo VII (gp49)-->3'-->5' exonuclease (gp43)-->DNA polymerase (gp43)-->DNA ligase (gp30). It is argued that the marker interference at very short distances may result from the same sequence of events during the final processing of recombinational intermediates.
authors.affiliation: Institute of Chemical Physics in Chernogolovka, Russian Academy of Sciences, Moscow Region.
authors.forename: V P
authors.initials: VP
authors.lastname: Shcherbakov
authors.forename: L A
authors.initials: LA
authors.lastname: Plugina
authors.forename: E A
authors.initials: EA
authors.lastname: Kudryashova
mesh_terms: D000483:Alleles; D017122:Bacteriophage T4 / Q000235:genetics*; D003433:Crosses, Genetic; D011088:DNA Ligases / Q000378:metabolism; D004260:DNA Repair; D004279:DNA, Viral / Q000235:genetics / Q000378:metabolism; D004259:DNA-Directed DNA Polymerase / Q000235:genetics / Q000502:physiology*; D004706:Endodeoxyribonucleases / Q000378:metabolism; D043211:Exodeoxyribonuclease V; D005090:Exodeoxyribonucleases / Q000378:metabolism; D008957:Models, Genetic; D011995:Recombination, Genetic; D014764:Viral Proteins / Q000235:genetics / Q000502:physiology*
chemical_list: D004279:DNA, Viral; D014764:Viral Proteins; C069983:gene 43 protein, Enterobacteria phage T4; D004259:DNA-Directed DNA Polymerase; D004706:Endodeoxyribonucleases; D005090:Exodeoxyribonucleases; D043211:Exodeoxyribonuclease V; C035571:endodeoxyribonuclease VII; D011088:DNA Ligases