Determination of Mutation Rates in Bacteriophage T4 by Unneighborly Base Pairs and a Genetic Analysis of the Error-Prone Repair System of Bacteriophage T4

Earlier studies showed that the 2-aminopurine-induced mutation frequency of a particular base pair can be influenced by the base pair adjacent or penultimate to the measure site. This study extends to 0.3 map units (about 20-80 base pairs) the distance at which a single base-pair substitution can exert such an effect. The presence of a base-pair substitution (defined as a ts mutation in the rIIA gene) reduces the spontaneous and 2-aminopurine-induced reversion of an rIIA amber mutation approximately three-fold. This ts mutation also reduces the 2-aminopurine-induced conversion is reduced about eight-fold, while the reversion of the ochre codon to glutamine (UAA (--->) CAA) is not affected. Selection controls demonstrate that the decrease is not due to selection against the ts marker. Control experiments measuring the efficiencies of plating of various homologous nonsense mutations on the appropriate amino-acid-inserting suppressor strains demonstrate that the observed reduction is not due to the nature of the protein produced by the amino acid at the nonsense site. These results demonstrate that the intrinsic mutability of a given site can be influenced by neighboring base pairs across "long" physical distances.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Microbiology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Conkling, Mark Alan

• Biology, Microbiology

Language dc:language

eng

Identifier

(UMI)AAI8203432

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/68093