title: Mutator mutations in bacteriophage T4 gene 42 (dHMC hydroxymethylase).
abstract: Temperature-sensitive mutations of bacteriophage T4 gene 42 produce diverse effects upon spontaneous mutation rate. G:C vector A:T transition rates are increased, often strongly; frameshift mutation rates are weakly increased; A:T vector G:C transition rates (and perhaps also A:T vector Py:Pu transversion rates) are decreased; and one G:C vector Py:Pu transversion rate is also decreased. These results, together with certain interactions between gene-42 mutator effects and both base analogue mutagenesis and the viral error-prone repair system, suggest that the dHMC hydroxymethylase coded by gene 42 affects mutation rates in a more complex manner than by the simple regulation of the concentration of the DNA precursor dHMCTP.
mesh_terms: D001483:Base Sequence; D002874:Chromosome Mapping; D003090:Coliphages / Q000201:enzymology*; D003596:Cytosine; D004261:DNA Replication; D004279:DNA, Viral; D005787:Gene Frequency; D005796:Genes; D008954:Models, Biological; D009154:Mutation; D013696:Temperature; D014166:Transferases
chemical_list: D004279:DNA, Viral; D003596:Cytosine; D014166:Transferases