Role of the core in CTnDOT integration

IntDOT is the tyrosine recombinase encoded by the Bacteroides conjugative transposon CTnDOT. It catalyzes integration and excision into and out of the bacterial host chromosome. Although it is a member of the well studied tyrosine recombinase family, IntDOT is of particular interest because it can catalyze recombination between substrates containing heterology in the overlap region. This tolerance for heterology suggests that IntDOT uses a different mechanism for recombination. IntDOT performs initial cleavage on the top strand adjacent to the D and B core sites. The first two bases within the overlap region are a conserved GC dinucleotide that provide the only sequence identity between the two substrates. I used complementary DNA oligonucleotides to invert the overlap region 180 degrees to relocate the GC dinucleotide to the bottom strand adjacent to the B’ core site of attB. I tested the inverted overlap attB site in an in vitro integration assay with wild-type attDOT and showed that integration still occurs, albeit in the opposite orientation relative to the wild type reaction. I used nicked attB substrates to show that initial cleavage of the inverted overlap attB substrate takes place on the bottom strand adjacent to the B’ core site, suggesting that the location of sequence identity within the overlap determines the site of initial cleavage. I confirmed this hypothesis by using an attB site containing a symmetric overlap sequence.

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

2012

Author dc:creator

• Laprise, Jennifer

Contributors dc:contributor

• Tapping, Richard I.
• Gardner, Jeffrey F.
• Slauch, James M.
• Kuzminov, Andrei

• Tyrosine recombinase
• CTnDOT
• Integration
• Conjugative transposon

Statement dc:rights

• Copyright 2012 Jennifer Laprise

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/34474

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/34474