title: Novel bacterial gas sensor proteins with transition metal-containing prosthetic groups as active sites.
abstract: CONCLUSIONS
  Gas molecules function as signaling molecules in many biological regulatory systems responsible for transcription, chemotaxis, and other complex physiological processes. Gas sensor proteins play a crucial role in regulating such biological systems in response to gas molecules.
  
  
  BACKGROUND
  New sensor proteins that sense oxygen or nitric oxide have recently been found, and they have been characterized by X-ray crystallographic and/or spectroscopic analysis. It has become clear that the interaction between a prosthetic group and gas molecules triggers dynamic structural changes in the protein backbone when a gas sensor protein senses gas molecules. Gas sensor proteins employ novel mechanisms to trigger conformational changes in the presence of a gas.
  
  
  RESULTS
  In gas sensor proteins that have iron-sulfur clusters as active sites, the iron-sulfur clusters undergo structural changes, which trigger a conformational change. Heme-based gas sensor proteins reconstruct hydrogen-bonding networks around the heme and heme-bound ligand.
  
  
  CONCLUSIONS
  Gas sensor proteins have two functional states, on and off, which are active and inactive, respectively, for subsequent signal transduction in response to their physiological effector molecules. To fully understand the structure-function relationships of gas sensor proteins, it is vital to perform X-ray crystal structure analyses of full-length proteins in both the on and off states.
authors: Okazaki Institute of Natural Sciences, National Institutes of Natural Sciences, Myodaiji, Okazaki, Japan. aono@ims.ac.jp
authors: Shigetoshi
authors: S
authors: Aono
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism*; D020134:Catalytic Domain; D005740:Gases / Q000032:analysis* / Q000378:metabolism*; D008667:Metalloproteins / Q000737:chemistry* / Q000378:metabolism*; D015398:Signal Transduction; D028561:Transition Elements / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D005740:Gases; D008667:Metalloproteins; D028561:Transition Elements