cis - and trans -Acting Elements Involved in Regulation of aniA , the Gene Encoding the Major Anaerobically Induced Outer Membrane Protein in Neisseria gonorrhoeae

Abstract

AniA (formerly Pan1) is the major anaerobically induced outer membrane protein in Neisseria gonorrhoeae. AniA has been shown to be a major antigen in patients with gonococcal disease, and we have been studying its regulation in order to understand the gonococcal response to anaerobiosis and its potential role in virulence. This study presents a genetic analysis of aniA regulation. Through deletion analysis of the upstream region, we have determined the minimal promoter region necessary for aniA expression. This 130-bp region contains a sigma 70-type promoter and an FNR (fumarate and nitrate reductase regulator protein) binding site, both of which are absolutely required for anaerobic expression. Also located in the minimal promoter region are three T-rich direct repeats and several potential NarP binding sites. This 80-bp region is required for induction by nitrite. By site-directed mutagenesis of promoter sequences, we have determined that the transcription ofaniA is initiated only from the sigma 70-type promoter. The gearbox promoter, previously believed to be the major promoter, does not appear to be active during anaerobiosis. The gonococcal FNR and NarP homologs are involved in the regulation of aniA, and we demonstrate that placing aniA under the control of thetac promoter compensates for the inability of a gonococcalfnr mutant to grow anaerobically.

Divergence and transcriptional analysis of the division cell wall (dcw) gene cluster in Neisseria spp.

“…This indicates that the gearbox promoter present in some CREEs is not transcriptionally active. A gearbox-like sequence has been identified previously 5¢ of the gonococcal aniA gene, for which promoter activity also could not be demonstrated (Householder et al, 1999). This is consistent with the absence of rpoS in these species (Tettelin et al, 2000), which is normally required for transcription from gearbox promoters (Vicente et al, 1991).…”

Identification of transcription activators that regulate gonococcal adaptation from aerobic to anaerobic or oxygen‐limited growth

“…Open bars, culture density (OD at 650 nm); hatched bars, b-galactosidase activity. (Householder et al, 1999). Only recently was evidence presented that transcription of mtrCDE genes encoding the multiple transferable resistance efflux pump is positively regulated by MtrA, a protein closely related to the AraC±XylS family of transcription activators (Rouquette et al, 1999).…”

“…Two lines of evidence establish that the same is not true for gonococci. First, inspection of the genome sequence for both gonococci and meningococci reveals only one gene for an FNR homologue, and we have previously reported that AniA is the only FNR-dependent protein that is essential for gonococcal nitrite reduction (Householder et al, 1999). Second, recent experiments have established that gonococcal reduction of nitric oxide to nitrous oxide is induced by NO independently of FNR (T. C. Householder, Fozo, J.…”

A physiologically significant role in nitrite reduction of the CcoP subunit of the cytochrome oxidasecbb3fromNeisseria gonorrhoeae

“…As in the meningococcus, Neisseria meningitidis, it conserves energy during electron transfer from physiological substrates via a membranebound respiratory chain to a single terminal cytochrome oxidase, cytochrome cbb 3 (Parkhill et al, 2000;Snyder et al, 2005;Chung et al, 2008;Deeudom et al, 2008). When the oxygen supply is growth-limiting, it also catalyses a truncated denitrification pathway in which nitrite is reduced to nitric oxide by AniA, a copper-containing nitrite reductase of the NirK family (Knapp & Clark, 1984;Clark et al, 1987;Mellies et al, 1997;Householder et al, 1999;Boulanger & Murphy, 2002). Nitric oxide is then reduced to N 2 O by a single-subunit nitric oxide reductase, NorB, that receives electrons directly from ubiquinol (Householder et al, 2000).…”