Poliovirus RNA polymerase requires a host factor to initiate RNA synthesis in vitro. The host factor was previously purified to near homogeneity from HeLa cells but was not assigned an enzymatic activity. This report describes the purification of a terminal uridylyltransferase that can act as host factor. By all criteria examined it is identical to the factor purified previously. It has the sam...

Ribonuclease P (RNase P), the ubiquitous endonuclease that catalyzes maturation of the 5'-end of tRNA in bacteria, is a ribonucleoprotein particle composed of one large RNA and one small protein. Two major structural types of bacterial RNase P RNA have been identified by phylogenetic comparative analysis: the A (ancestral) and B (Bacillus) types. The RNase P protein from Thermotoga maritima, a ...

In plant mitochondria, as in most other genetic systems, several enzymatic processing and modification steps are required to yield mature tRNAs from primary transcripts. Three of the enzymes involved, RNase P, 3'-processing activity, and tRNA nucleotidyl transferase, were identified in potato (Solanum tuberosum) mitochondria and have been separated by several purification steps. RNase P was par...

Sephadex-binding RNA ligands (aptamers) were obtained through in vitro selection. They could be classified into two groups based on their consensus sequences and the aptamers from both groups showed strong binding to Sephadex G-100. One of the highest affinity aptamers, D8, was chosen for further characterization. Aptamer D8 bound to dextran B512, the soluble base material of Sephadex, but not ...

Several proteins of heterogeneous nuclear ribonucleoprotein (hnRNP) particles display very high binding affinities for different ribonucleotide homopolymers. The specificity of some of these proteins at high salt concentrations and in the presence of heparin allows for their rapid one-step purification from HeLa nucleoplasm. We show that the hnRNP C proteins are poly(U)-binding proteins and com...

A deletion mutation in the gene rpoZ of Mycobacterium smegmatis causes reduced growth rate and a change in colony morphology. During purification of RNA polymerase from the mutant strain, the subunit undergoes fragmentation but the fragments remain associated with the enzyme and maintain it in an active state until the whole destabilized assembly breaks down in the final step of purification. C...

The complete nucleotide sequence was determined for the putative RNA polymerase (183K protein) gene of tobacco mosaic virus (TMV) OM strain, which differed from the related strain, vulgare, by 51 positions in its nucleotide sequence and 6 residues in its amino acid sequence. Three segments of this 183K protein, each containing the sequence motif of methyltransferase (M), helicase (H), or RNA-de...

Isolation of high-quality RNA free of contaminants, such as polyphenols, proteins, plant secondary metabolites, and genomic DNA from plant tissues, is usually a challenging but crucial step for molecular analysis. We developed a novel protocol based on the cetyltrimethylammonium bromide method to isolate high-quality RNA from blackberry plant tissues, especially fruits. Most DNA was remove...

Most strategies for mRNA isolation involve as a first step isolation of total RNA and as a second step selection of poly A + RNA by affinity chromatography on oligo dT cellulose columns. Here we report a novel method which allows isolation of poly A + RNA directly from crude plant tissue without first preparing total RNA or any other purification steps. The method is based upon the addition of ...