Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.13.3 (histidine kinase)
 2,405 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An enzyme of molecular weight 32,000 comprising a single subunit has been isolated from whole cell extracts of the yeast Saccharomyces cerevisiae. In vitro, the enzyme transfers the gamma phosphate of ATP to a protein substrate, histone H4, to produce an alkali-stable phosphorylation. Modification of the substrate histidine with diethylpyrocarbonate prevented phosphorylation. Phosphoamino acid analysis of the phosphorylated substrate showed the presence of 1-phosphohistidine. Hence, the isolated enzyme is a protein histidine kinase. A novel assay for acid-labile alkali-stable protein phosphorylation was used in the purification of the kinase activity to a final specific activity of 2,700 nmol/15 min/mg. The purified enzyme phosphorylates specifically histidine 75 in histone H4 and does not phosphorylate histidine 18 nor histidine residues in any other core histone. Steady state kinetic data are consistent with an ordered sequential reaction with Km values for Mg-ATP and histone H4 of 60 and 17 microM, respectively. The protein histidine kinase requires a divalent cation such as Mg2+, Co2+, or Mn2+ but will not use Ca2+, Zn2+, Cu2+, Fe2+, spermine, or spermidine. This is the first purification of an enzyme that catalyzes N-linked phosphorylation in proteins.
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PMID:Purification of a protein histidine kinase from the yeast Saccharomyces cerevisiae. The first member of this class of protein kinases. 202 10

The czc determinant, which mediates resistance to Co2+, Zn2+ and Cd2+ in Alcaligenes eutrophus CH34 by cation efflux, is regulated by a two-component regulatory system composed of the sensor histidine kinase CzcS and the response activator CzcR (in addition to other components previously described). Regulatory genes are arranged in an upstream regulatory region (URR) and a downstream regulatory region (DRR). Transcription of czcCBA and of the URR was regulated by heavy-metal cations. DNA sequencing of the region downstream of czcD revealed the presence of the czcR and czcS genes which together with czcD form the DRR. Regulation of the DRR was studied with a czcD::lacZ translational fusion and a czcS::lux transcriptional fusion. Expression of both genes is also regulated by heavy metals. The genes of the URR yielded three mRNAs of approx. 1200, 500 and 200 nucleotides, respectively. The genes czcCBA for the cation/proton antiporter CzcCBA were transcribed by one operon as a transcript of 6200 nucleotides.
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PMID:Two-component regulatory system involved in transcriptional control of heavy-metal homoeostasis in Alcaligenes eutrophus. 904 83