The P22 Xis Protein: Regulation of Bacteriophage P22 Site -Specific Recombination

Mutants of P22 Xis were isolated and assayed for excision system in vivo, to quantify their excision activity relative to wild-type Xis. Mutants S18F, R19A, G29S, G29D, A33P, R35C, D37G, S43F, S43P, P44L, L46F, A51T, and A51V were found to be defective in stimulating excision. Additionally, truncation mutants S66Z, K76Z, and D97Z were decreased in function about five-fold. In contrast, truncation mutants Q57Z and a mutant with the first 21 amino acids deleted were completely defective. Substitution mutants at R105, K107, and R109 revealed that this region stimulates the reactaion. A subset of Xis mutants were purified and assayed by EMSA and crosslinking studies. All purified mutants formed multimers by crosslinking, but L15F, K16E, A33P, S43F, and A55T were defective in DNA binding. Furthermore, L46F bound DNA with a weaker affinity but still formed specific complexes.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Biochemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Mattis, Aras Nikodemas

Contributors dc:contributor

• Gumport, Richard I.

• Chemistry, Biochemistry

Language dc:language

eng

Identifier

(MiAaPQ)AAI3290313

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/84842