Femtomolar sensitivity of a NO sensor from Clostridium botulinum.
Nitric oxide (NO) is extremely toxic to Clostridium botulinum, but its molecular targets are unknown. Here, we identify a heme protein sensor (SONO) that displays femtomolar affinity for NO. The crystal structure of the SONO heme domain reveals a previously undescribed fold and a strategically placed tyrosine residue that modulates heme-nitrosyl coordination. Furthermore, the domain architecture of a SONO ortholog cloned from Chlamydomonas reinhardtii indicates that NO signaling through cyclic guanosine monophosphate arose before the origin of multicellular eukaryotes. Our findings have broad implications for understanding bacterial responses to NO, as well as for the activation of mammalian NO-sensitive guanylyl cyclase.
Nioche
Pierre
P
Structural Biology Research Center and Department of Biochemistry and Molecular Biology, University of Texas Medical School, Houston, TX 77030, USA.
Berka
Vladimir
V
Vipond
Julia
J
Minton
Nigel
N
Tsai
Ah-Lim
AL
Raman
C S
CS
D000332:Aerobiosis; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D005075:Biological Evolution; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002633:Chemotaxis; D016825:Chlamydomonas reinhardtii / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D003014:Clostridium botulinum / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D018360:Crystallography, X-Ray; D004578:Electron Spin Resonance Spectroscopy; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development; D006162:Guanylate Cyclase; D006418:Heme / Q000737:chemistry / Q000378:metabolism; D006420:Hemeproteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D006860:Hydrogen Bonding; D008024:Ligands; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009569:Nitric Oxide / Q000378:metabolism*; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011524:Protoporphyrins / Q000032:analysis / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D015398:Signal Transduction; D000071756:Soluble Guanylyl Cyclase; D055672:Static Electricity; D046968:Thermoanaerobacter / Q000737:chemistry
D001426:Bacterial Proteins; D002352:Carrier Proteins; D006420:Hemeproteins; D008024:Ligands; D011524:Protoporphyrins; D018160:Receptors, Cytoplasmic and Nuclear; C494122:SONO protein, Clostridium botulinum; C448299:iron protoporphyrin IX; D009569:Nitric Oxide; D006418:Heme; D006162:Guanylate Cyclase; D000071756:Soluble Guanylyl Cyclase