Figure 10. Proposed pathway for electron transfer from NADH to nitric oxide, oxygen and nitrite in N. meningitidis and N. gonorrhoeae.

Electron flow from cytoplasmic reductants (NADH, succinate, etc. shown as [H]) to terminal electron acceptors NO, O₂, and NO₂ are shown by arrows. The unique pathway associated with the tri-heme CcoP form in N. gonorrhoeae (absent in N. meningitidis) is designated by the red arrow. UQ, ubiquinone; NirK, nitrite reductase; NorB, nitric oxide reductase. The model is based on data from this work and that found in [51], [52], [78].