Open AccessEffect of host bacteria genotype on spontaneous reversions of Bacillus subtilis bacteriophage Φ29 sus17 nonsense codon
Author(s) -
Fučík Vladimír,
Beran Jaroslav,
Krásný Libor,
Jonák Jiří
Publication year - 2000
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2000.tb08948.x
Subject(s) - bacillus subtilis , bacteriophage , genotype , nonsense , bacteria , microbiology and biotechnology , biology , host (biology) , genetics , escherichia coli , gene
Gene 17 of Bacillus subtilis bacteriophage Φ29 is an early gene playing a role in DNA replication. Its mutant sus17(112) carries the TAA nonsense triplet at the fifth codon of the gene. We isolated and sequenced 73 spontaneous revertants producing normal‐size plaques on bacteria without an informational suppressor gene. In all revertants, the TAA triplet was changed by a one‐base substitution and the sequences CAA, AAA, TTA, TAC and TAT were recovered at its place. The spectrum of these mutations was markedly influenced by the genotype of the bacteria in which the revertants arose. In agreement with the results described in Escherichia coli , the ratio of transversions to transitions (CAA being the only transition acceptable) was higher in strains harboring the functional allele recA + than in those with recA4 . Our results support the idea that also in the Gram‐positive B. subtilis , the spectra of spontaneous mutations are specifically modified by an SOS function. It is assumed that the single‐stranded DNA chains generated in the course of phage DNA replication might act as an inducing factor.