Proteins Histidine

Histidine phosphatases and aspartate phosphatases are well established in lower organisms, mainly in bacteria and in context with two-component-systems . Reversible phosphorylation of histidine residues in vertebrates is in its infancy. The first protein histidine phosphatase (PHP) from mammalian origin was identified just recently. The soluble 14 kD protein does not resemble any of the other phosphatases. ATP-citrate lyase and the (3-subunit of heterotrimeric GTP-binding proteins are substrates of PHP thus touching both, metabolic pathways and signal transduction [4]. 

Cysteine can bind to either one or two metal ions, and is frequently found as a ligand to iron (in Fe-S clusters—see later) and to Cu+ (for example in the copper chaperones, which transfer copper to specific copper-binding proteins). Histidine can bind metal ions in two... 

Phosphate transfer between the protein histidine kinase HupT and the response regulator HupR... 

Figure 3.12 Phosphate transfer between the protein histidine kinase HupT and the response regulator HupR. HupT (7 pmol) was phosphorylated at 30°C with [y- PJATP for 5 min, before addition of wild-type (HupR) or mutated (HupR-DS4E) HupR protein. Aliquots were withdrawn 5 min or 20 min after addition of HupR and analysed by SDS polyacrylamide gel electrophoresis. HupT20 HupT was phosphorylated for 20 min in the absence of HupR.

Our biomimetic investigations have focused on the metalloproteins hemocyanin (He) (11-17) and tyrosinase (11,12,14,16,18,29), which contain two copper ions in their active center. The function of hemocyanin is to bind and transport dioxygen in the hemolymph of molluscs and arthropods. Studies employing EXAFS spectroscopy have shown that in the deoxy form, two (19-21) or three (13,21) imidazole units fiom protein histidine residues coordinate to each cuprous ion. Upon addition of O2 to give oxy-Hc, considerable changes take place in the coordination sphere giving rise to tetragonally coordinated Cu(II) ions... 

Zu, X.L., BesanL P.G., Imhof, A. and Attwood, P.V. (2007) Mass spectrometric analysis of protein histidine phosphorylation. Amino Acids,... 

Motojima, K. Goto, S. A protein histidine kinase induced in rat liver by peroxisome proliferators. In vitro activation by Ras protein and guanine nucleotides. FEBS Lett., 319, 75-79 (1993)... 

Wei, Y.F. Matthews, H.R. Identification of phosphohistidine in proteins and purification of protein-histidine kinases. Methods Enzymol., 200, 388-414 (1991)... 

Huang, J. Wei, Y.K. Osterberg, L. Matthews, H.R. Purification of a protein histidine kinase from the yeast Saccharomyces cerevisiae. The first member of this class of protein kinases. J. Biol. Chem., 266, 9023-9031 (1991)... 

Wei, Y.R Morgan, J.E. Matthews, H.R. Studies of histidine phosphorylation by a nuclear protein histidine kinase show that histidine-75 in histone H4 is masked in nucleosome core particles and in chromatin. Arch. Biochem. Biophys., 268, 546-550 (1989)... 

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