Inositol pyrophosphates, also designated inositol diphosphates, possess high-energy beta-phosphates that can pyrophosphorylate proteins and regulate various cellular processes. They are formed by a family of inositol hexakisphosphate kinases (IP6Ks). We have created mice with a targeted deletion of IP6K1 in which production of inositol pyrophosphates is markedly diminished. Defects in the mutan...

The enzyme, polynucleotide phosphorylase, catalyzes the polymerization of nucleoside diphosphates to polyribonucleotides with the formation of inorganic orthophosphate (1, 2). The reaction is readily reversible, and the phosphorolysis of polyribonucleotides has been studied extensively (3-6). Several recent reviews (7-9) afford extensive summaries of the literature. In the accompanying paper (l...

Bacteriophage phi 6 contains three segments of double-stranded RNA. The procapsid consists of proteins P1, P2, P4, and P7, which are encoded by the viral L segment. cDNA copies of this segment have been cloned into plasmids that direct the production of these proteins, which assemble into polyhedral procapsids. These procapsids are capable of packaging plus-sense phi 6 RNA in the presence of nu...

Nucleoside diphosphokinase from Salmonella typhimurium has been purified and characterized. In many respects, the enzyme is similar to those from higher organisms in that it has a broad speciCcity for both phosphate donor and recipient and that it functions via a ping-pong mechanism. The enzyme activity of cells is very high at all growth rates but decreases as growth rate increases. Evidence i...

The acid protease which is activated by ATP and which catalyzes production of fragments of parathyroid hormone similar to those produced in vivo was shown to be cathepsin D. Purified cathepsin D from bovine kidney and spleen is activated by ATP and other nucleoside triphosphates, and to a much lesser extent by nucleoside diphosphates and pyrophosphate. These findings suggest that cathepsin D ma...

Method The object of our study is to develop newer nucleoside phosphonate analogs bearing unsaturation and modifications in heterogenous bases and prediction of their antiHIV potential. Designing is done keeping the Lipinski’s Rule of Five in focus. The diphosphates of compounds have been docked into the active site of wild type HIVRT (PDB: ID 2B6A). The forcefield of the Chemistry at Harvard M...

Terpene synthases catalyze the conversion of linear prenyl-diphosphates to a multitude of hydrocarbon skeletons with often high regioand stereoselectivity. These remarkable enzymes all rely on a shared fold for activity, namely, the class I terpene cyclase fold. Recent work has illuminated the catalytic strategy used by these enzymes to catalyze the arguably most complex chemical reactions foun...

Highly purified rho termination factor from Escherichia coli catalyzes an RNA-dependent hydrolysis of ribonucleoside triphosphates to nucleoside diphosphates and inorganic phosphate. In the presence of poly(C), a specific activity of 100 mumole of ATP hydrolyzed per min/mg has been measured. The phosphohydrolase activity appears to be associated with the protein responsible for termination of R...