An enzyme in rat-liver cytosol transferred the gamma-phosphoryl of GTP to serine and threonine residues of at least four proteins (S6, S10, S14 or S15, and S17) of the small (40S) subunit of rat-liver ribosomes. A number of nonribosomal proteins in the enzyme preparation were also phosphorylated; they were preferentially and tightly bound to the large subunit. The enzyme could be distinguished ...

Incubation of hen oviduct membranes with UDP-[14C]N-acetylglucosamine (GlcNAc) leads to the formation of four endogenously labeled lipids. One of these lipids has not previously been characterized. Based on its chromatographic behavior on SG-81 paper and DEAE-cellulose, it is a monophosphate diester. The oviduct lipid is extremely sensitive to mild acid hydrolysis and, based on a comparison wit...

Bacterial motility and gene expression are controlled by a family of phosphorylated response regulators whose activities are modulated by an associated family of protein-histidine kinases. In chemotaxis there are two response regulators, CheY and CheB, that receive phosphoryl groups from the histidine kinase, CheA. Here we show that the response regulators catalyze their own phosphorylation in ...

The Escherichia coli mannitol transporter (II(Mtl)) comprises three domains connected by flexible linkers: a transmembrane domain (C) and two cytoplasmic domains (A and B). II(Mtl) catalyzes three successive phosphoryl-transfer reactions: one intermolecular (from histidine phosphocarrier protein to the A domain) and two intramolecular (from the A to the B domain and from the B domain to the inc...

HPr, a central component of the phosphoenolpyruvate-dependent phosphotransferase system, can exist in Escherichia coli in a phosphorylated (PHPr) and a nonphosphorylated form. We show that, beside the normal transfer of the phosphoryl group from PHPr to enzymes II and III, PHPr can phosphorylate other HPr molecules in an autocatalytic exchange reaction. The reaction is very fast but is inhibite...

Human ubiquitous mitochondrial creatine kinase (uMtCK) is responsible for the regulation of cellular energy metabolism. To investigate the phosphoryl-transfer mechanism catalyzed by human uMtCK, in this work, molecular dynamic simulations of uMtCK∙ATP-Mg2+∙creatine complex and quantum mechanism calculations were performed to make clear the puzzle. The theoretical studies hereof revealed that hu...