A Bacterial Nose for NO

Science's STKE  30 Nov 2004:
Vol. 2004, Issue 261, pp. tw435
DOI: 10.1126/stke.2612004tw435

Nitric oxide is an important signaling molecule in mammals, where it acts in part when sensed by a heme protein, soluble guanylate cyclase. Nioche et al. searched for ancestral proteins with related NO-binding heme domains in the bacterium Clostridium botulinum. NO is toxic to C. botulinum, and the bacterium actively moves away from nitrite-preserved meat. The authors identified a bacterial protein with an extreme (femtomolar) binding affinity for NO and elucidated the crystal structure of a related molecule from Thermoaneaerobacter tencongensis. NO-binding domains thus provide prokaryotes with a highly sensitive sensor for NO.

P. Nioche, V. Berka, J. Vipond, N. Minton, A.-L. Tsai, C. S. Raman, Femtomolar sensitivity of a NO sensor from Clostridium botulinum. Science 306, 1550-1553 (2004). [Abstract] [Full Text]