The requirements for conjugal DNA synthesis in the donor strain during Flac transfer
- 1 July 1978
- journal article
- research article
- Published by Elsevier BV in Journal of Molecular Biology
- Vol. 122 (3), 287-300
- https://doi.org/10.1016/0022-2836(78)90191-2
Abstract
Although neither rifampicin nor spectinomycin had any effect on the frequency of Flac transfer by a sensitive donor, rifampicin but not spectinomycin prevented donor conjugal DNA synthesis as measured in matings between a dnaB donor and a tdk recipient. An untranslated RNA species is therefore probably required for this synthesis, although transfer took place even in its absence. Donor conjugal DNA synthesis was abolished in a dnaE donor, showing that DNA polymerase III is responsible for this process; again, plasmid DNA transfer was not affected. Flac mutants lacking the F pilus gave neither donor conjugal DNA synthesis nor plasmid DNA transfer, probably because they could not receive a “mating signal” to activate the transfer process. The products of traI and traM were also required both for donor conjugal DNA synthesis and for physical transfer of plasmid DNA, probably being involved in the conversion of covalently closed circular plasmid DNA into the open circular form that is the substrate for the independent although normally simultaneous synthesis and transfer steps. In contrast, donor conjugal DNA synthesis took place at a normal rate in both piliated traG and traN mutants, and at a reduced rate in traD mutants, although in no case was there physical transfer of plasmid DNA. These gene products are therefore required for DNA transfer to the recipient, and in addition, the absence of the traD product may hinder DNA synthesis. Based upon these results, a scheme for the processing of DNA during conjugation is presented.This publication has 34 references indexed in Scilit:
- Bacterial plasmids with particular reference to their replication and transfer propertiesProgress in Biophysics and Molecular Biology, 1978
- Identification of the structural gene for F-pilinJournal of Molecular Biology, 1976
- DNA synthesis during bacterial conjugation: II. Is DNA replication in the Hfr obligatory for chromosome transfer ?Journal of Molecular Biology, 1973
- On the mechanism of conjugation in Escherichia coli K12Molecular Genetics and Genomics, 1973
- Genetics of the F Sex Factor in EnterobacteriaceaePublished by Springer Science and Business Media LLC ,1973
- Conjugational Complementation Analysis of Transfer-Deficient Mutants of F lac in Escherichia coliJournal of Bacteriology, 1972
- Beginning a Genetic Analysis of Conjugational Transfer Determined by the F Factor inEscherichia coliby Isolation and Characterization of Transfer-Deficient MutantsJournal of Bacteriology, 1971
- On the mechanism of conjugation in Escherichia coli K 12Molecular Genetics and Genomics, 1968
- Properties of sex factor and related episomes isolated from purified Escherichia coli zygote cellsJournal of Molecular Biology, 1968
- Effect of nalidixic acid on conjugational transfer and expression of episomal Lac genes in Escherichia coli K12Journal of Molecular Biology, 1967