Escherichia coli class Ib ribonucleotide reductase (RNR) converts nucleoside 5'-diphosphates to deoxynucleoside 5'-diphosphates and is expressed under iron-limited and oxidative stress conditions. This RNR is composed of two homodimeric subunits: alpha2 (NrdE), where nucleotide reduction occurs, and beta2 (NrdF), which contains an unidentified metallocofactor that initiates nucleotide reduction...

Z-prenyl diphosphate synthases catalyze the sequential condensation of isopentenyl diphosphate with allylic diphosphates to synthesize polyprenyl diphosphates. In mycobacteria, these are precursors of decaprenyl phosphate, a molecule which plays a central role in the biosynthesis of essential mycobacterial cell wall components, such as the mycolyl-arabinogalactan-peptidoglycan complex and lipoa...

Rat liver microsomes catalyze the hydrolysis of the triphosphates of adenosine, guanosine, uridine, cytidine, and inosine into the corresponding diphosphates and inorganic orthophosphate. The activities are stimulated by Na(2)S(2)O(4), and inhibited by atebrin, chlorpromazine, sodium azide, and deaminothyroxine. Sodium deoxycholate inhibits the ATPase activity in a progressive manner; the relea...

The preparation of synthetic ribonucleic acid in which one of the nucleotide species is labeled with P32, makes possible studies on the distribution of the labeled nucleotide in the polynucleotide chain. Fig. 1 presents the structure of a polynucleotide in which labeled adenylic acid is randomly distributed. Hydrolysis of such a polymer with snake venom phosphodiesterase (Fig. 1A) will yield a ...

The identification of a myo-inositol-containing phospholipid isolated from beef brain (1) as a triphosphoinositide has been reported in earlier publications from this laboratory (2) and in a note by Dittmer and Dawson (3). It has been established (2) by periodate oxidation that the myo-inositol moiety in the intact triphosphoinositide is substituted on the 1, 4, and 5 or 6 hydrosyl groups. When...

Isoprenyl diphosphate synthases (IDSs) produce the ubiquitous branched-chain diphosphates of different lengths that are precursors of all major classes of terpenes. Typically, individual short-chain IDSs (scIDSs) make the C10, C15, and C20 isoprenyl diphosphates separately. Here, we report that the product length synthesized by a single scIDS shifts depending on the divalent metal cofactor pres...

In vitro enzyme-based ATP regeneration systems are important for improving yields of ATP-dependent enzymatic reactions for preparative organic synthesis and biocatalysis. Several enzymatic ATP regeneration systems have been described but have some disadvantages. We report here on the use of polyphosphate:AMP phosphotransferase (PPT) from Acinetobacter johnsonii strain 210A in an ATP regeneratio...

Pyrophosphate anions play key roles in various biological and chemical processes. During the last few years, many exciting results have emerged regarding the development of fluorescent and colorimetric sensors for this biologically important species. In this review, we will cover the fluorescent and colorimetric chemosensors developed for the detection of pyrophosphate (PPi) since 2010.

Stable IspF substrate analogs were synthesized. In the presence of substrate analogs, the E. coli IspF-MEP complex shows activities distinct from IspF, and bisphosphonates (BP) behave differently than their diphosphate (DP) counterparts. Bisphosphonate analogs activate and/or stabilize IspF, and only the closest structural substrate analog weakly inhibits the IspF-MEP complex.