Nucleotide binding by the histidine kinase CheA.
To probe the structural basis for protein histidine kinase (PHK) catalytic activity and the prospects for PHK-specific inhibitor design, we report the crystal structures for the nucleotide binding domain of Thermotoga maritima CheA with ADP and three ATP analogs (ADPNP, ADPCP and TNP-ATP) bound with either Mg(2+) or Mn(2+). The conformation of ADPNP bound to CheA and related ATPases differs from that reported in the ADPNP complex of PHK EnvZ. Interactions of the active site with the nucleotide gamma-phosphate and its associated Mg(2+) ion are linked to conformational changes in an ATP-lid that could mediate recognition of the substrate domain. The inhibitor TNP-ATP binds CheA with its phosphates in a nonproductive conformation and its adenine and trinitrophenyl groups in two adjacent binding pockets. The trinitrophenyl interaction may be exploited for designing CheA-targeted drugs that would not interfere with host ATPases.
Division of Biology, California Institute of Technology, 1200 East California Blvd., Pasadena, California 91125, USA.
A M
AM
Bilwes
C M
CM
Quezada
L R
LR
Croal
B R
BR
Crane
M I
MI
Simon
D000244:Adenosine Diphosphate / Q000378:metabolism*; D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism*; D001426:Bacterial Proteins; D001665:Binding Sites; D002413:Cations, Divalent / Q000378:metabolism; D002850:Chromatography, Gel; D018360:Crystallography, X-Ray; D000071677:Histidine Kinase; D006860:Hydrogen Bonding; D008274:Magnesium / Q000378:metabolism; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism*; D000072236:Methyl-Accepting Chemotaxis Proteins; D008958:Models, Molecular; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases / Q000737:chemistry* / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D012997:Solvents; D020124:Thermotoga maritima / Q000201:enzymology*
D001426:Bacterial Proteins; D002413:Cations, Divalent; D008565:Membrane Proteins; D000072236:Methyl-Accepting Chemotaxis Proteins; D047428:Protein Kinase Inhibitors; D012997:Solvents; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D011494:Protein Kinases; D000071677:Histidine Kinase; D000251:Adenosine Triphosphatases; D008274:Magnesium