Northern Illinois University, Biological Sciences, Dekalb, IL 60115
Neisseria gonorrhoeae is the pathogen responsible for the sexually transmitted infection gonorrhea. Since gonorrhea is a prevalent infection disease, many antibiotics such as penicillin and ceftriaxone have been used to fight the bacterium, and treat the infection. However, a vaccine has yet to be discovered that can potentially prevent the infection from initially occurring. Due to the constant variability of the pilus structure of the bacterium, Neisseria gonorrhoeae is extremely difficult to develop a vaccine for. Periodically, the bacterium will alter the structure of the pilus by slightly varying the genomic sequence responsible for making the pilE polypeptide. This occurs through a process called genetic recombination. In N. gonorrhoeae, there are a set of transcriptionally silent genes, called the pilS genes, which translocate a segment of their DNA, into the variable regions of the pilE gene. This process of genetic recombination is dependent on the RecA protein. Very little is known is about transcriptional regulation of the pilE gene. During our studies on pilE gene expression, mRNA sequences very similar to the pilS loci were shown being transcribed leading to the possibility that the pilS sequences are perhaps transcriptionally active, indicating possible promoter sites within the loci. Using the program Artemis, two such possible promoter sites in pilS 2 were indicated. Site directed mutagenesis to slightly alter the potential promoter sites will determine whether or not the sites can be confirmed as promoter sites. Following mutagenesis, if mRNA is absent, then this will indicate that the pilS genes are indeed being transcribed.
[Abstract (DOC)]