The Escherichia coli endoribonuclease RNase E is essential for RNA processing and degradation. Earlier work provided evidence that RNase E exists intracellularly as part of a multicomponent complex and that one of the components of this complex is a 3'-to-5' exoribonuclease, polynucleotide phosphorylase (EC 2.7.7.8). To isolate and identify other components of the RNase E complex, FLAG-epitope-...

The possible backbone phosphodiester conformations in a dinucleoside monophosphate and a dinucleoside triphosphate have been investigated by semiempirical energy calculations. Conformational energies have been computed as a function of the rotations omega' and omega about the internucleotide P-O(3') and P-O(5') linkages, with the nucleotide residues themselves assumed to be in one of the prefer...

Chloroquine and primaquine inhibited polypeptide formation directed by poly U and random poly A,G,U in a rat liver cell-free system. It was necessary to preincubate the drug and polynucleotide before addition to the cell-free system to observe this inhibition. These antimalarials also decreased the binding of poly U to ribosomes under these conditions. No inhibition of polypeptide syntheses or ...

Polynucleotide kinase from E. coli infected with the PseT 1 mutant of bacteriophage T4 has been isolated. The PseT 1 enzyme purifies similarly to normal polynucleotide kinase and effectively transfers the gamma phosphate of ATP to the 5' terminal hydroxyl of DNA and RNA. The PseT 1 and normal enzymes require similar magnesium ion concentrations, have the same pH optima and are both inhibited by...

CsgD and cyclic-3',5'-di-guanylate are key regulators of biofilm formation in Salmonella enterica serovar Typhimurium. Our results show that polynucleotide phosphorylase and NlpI oppositely altered expression of CsgD. Polynucleotide phosphorylase and NlpI also had opposite effects on the expression of yjcC, which codes for a cyclic-3',5'-di-guanylate phosphodiesterase affecting CsgD expression.

The gene for the enzyme guanosine pentaphosphate synthetase I (GPSI) from Streptomyces antibioticus has been cloned and sequenced. The cloned gene functioned as a template in the streptomycete coupled transcription-translation system and directed the synthesis of a protein with the properties expected for GPSI. Sequencing of the cloned gene identified an open reading frame of 740 amino acids wh...

A known interferon stimulator, polyriboinosinic acid:polyribocytidylic acid (rI:rC), was shown to have a protective effect against a highly tumorigenic variant of the murine sarcoma virus (Moloney) designated as (MSV-PV). Mice treated intraperitoneally with different regimens of rI:rC survived significantly longer than untreated controls. The treatment was effective whether the infection with M...

A recent screen of 6,961 siRNAs to discover possible synthetic lethal partners of the DNA repair protein polynucleotide kinase/phosphatase (PNKP) led to the identification of the potent tumor suppressor phosphatase and tensin homolog deleted on chromosome 10 (PTEN). Here, we have confirmed the PNKP/PTEN synthetic lethal partnership in a variety of different cell lines including the PC3 prostate...

Escherichia coli isolated from 2,126 children in Thailand and the Philippines was examined for enterotoxin production and for DNA hybridization with synthetic oligonucleotide and cloned polynucleotide enterotoxin gene probes. A total of 233 infections with E. coli that were detected by one or more of these assays were identified. Of the infections, 75% (164/233) were identified by all three met...