Transcript analysis of nrrF, a Fur repressed sRNA of Neisseria gonorrhoeae.

Like most microorganisms, Neisseria gonorrhoeae alters gene expression in response to iron availability. The ferric uptake regulator Fur has been shown to be involved in controlling this response, but the extent of this involvement remains unknown. It is known that in addition to working directly to repress gene expression, Fur may also work indirectly by controlling additional regulatory elements. Using in silico analysis, we identified a putative small RNA (sRNA) homolog of the meningococcal nrrF locus, and demonstrate that this sRNA is iron-repressible, suggesting that this is the gonococcal analog of the rhyB locus in Escherichia coli. Quantitative real-time RT-PCR analysis indicates that this transcript may also be temporally regulated. Transcript analysis identified the 5' start of the transcript, using a single reaction, fluorescent-based, primer extension assay. This protocol allows for the rapid identification of transcriptional start sites of RNA transcripts, and could be used for high-throughput transcript mapping.