Mutational Analysis of NBU1 Attachment Sites Reveals a Novel Recombination Mechanism

NBU1 is a 10.3 kbp mobilizable transposon that is normally integrated in the chromosome of its Bacteroides host. Bacteroides are the predominant member of the human intestinal tract microflora, and are opportunistic pathogens that can cause life-threatening infections. A recent survey of Bacteroides isolates has shown an increase in tetracycline resistance, which has been attributed to mobilizable and related conjugative transposons. NBU1 integrates site specifically into the Bacteroides thetaiotaomicron chromosome primary target site, attBT1-1. NBU1 integrase (IntN1) catalyzes recombination of the NBU1 attachment site, attN1, and the attBT1-1 site. IntN1 is a member of the lambda family of tyrosine site-specific recombinases. However, the mechanisms of integration of NBU1 and related mobilizable transposons have not been fully characterized and may be unique. Previous studies have shown that NBU1 has a broad host range and can integrate nonspecifically in Escherichia coli. An in vivo E. coli integration system has been developed to study the nucleotide requirements for NBU1 site-specific integration. This in vivo system has been used to determine the minimal attN1 site. Mutational analysis of the attN1 site has indicated that several nucleotide sequence motifs in the attN1 site are required for integration. Analysis of attN1 and attBT1-1 mutations has also led to the conclusion that recombination mechanism of NBU1 is novel.

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

2015

Author dc:creator

• Schmidt, John William

Contributors dc:contributor

• Gardner, Jeffrey F.

• Biology, Microbiology

Language dc:language

eng

Identifier

(MiAaPQ)AAI3153417

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/86675