Characterization of the Gifsy-1 Phage Excisionase

The Gifsy-1 phage is a temperate bacterial virus that infects its host, Salmonella enterica serovar Typhimurium. During lysogeny, the phage integrates site-specifically into a single bacterial attachment sequence in the Salmonella chromosome. The reaction involves recombination between the phage attachment sequence (attP) and the bacterial attachment sequence (attB). The phage encoded enzyme, Gifsy-1 integrase (Int), catalyzes this recombination reaction between the phage chromosome and the bacterial host chromosome. The reaction requires and accessory protein, Integration Host Factor (IHF). This forward recombination reaction between phage encoded attP and host encoded attB is referred to as phage integration. Integration results in the creation of two attachment sites that border the integrated phage chromosome, attL and attR. It is believed that the Gifsy-1 phage Int catalyzes a reaction that is chemically identical to that described for the lambda Int protein. This reaction results in chimeric products of the recombination reaction, attL and attR, in which one-half of the att sequence is composed of host DNA and the remainder is composed of phage DNA. The reaction is not directly reversible and requires another phage encoded protein, the Gifsy-1 excisionase (Xis) protein for the integrated phage to excise from the host chromosome.

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

• Flanigan, Asa

Contributors dc:contributor

• Gardner, Jeffrey F.

• Biology, Microbiology

Identifier

(UMI)AAI3337779

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/72514