We have analyzed the subcellular localization of 125I-labeled ribonuclease A and ribonuclease S-protein (residues 21-124) after erythrocyte-mediated microinjection into confluent cultures of IMR-90 human lung fibroblasts. Microinjected cells were fractionated by two consecutive Percoll gradients, and the distribution of radioactive ribonuclease A and S-protein was compared to patterns for known...

Ribonuclease P is the endoribonuclease responsible for the removal of leader sequences from tRNA precursors. Ribonuclease P is a ribonucleoprotein, and in bacteria the RNA alone is capable of pre-tRNA processing in vitro, i.e. it is a catalytic RNA. The Ribonuclease P Database is a compilation of ribonuclease P sequences, sequence alignments, secondary structures, three-dimensional models and a...

Santer, Melvin (Haverford College, Haverford, Pa.), and Josephine R. Smith. Ribonuclease sensitivity of Escherichia coli ribosomes. J. Bacteriol. 92:1099-1110. 1966.-The ribonucleic acid (RNA) contained in 70S ribosomes and in 50S and 30S subunits was hydrolyzed by pancreatic ribonuclease. A 7% amount of the RNA was removed from the 70S particle; at 10(-4)m magnesium concentration, a maximum of...

Greene (1) found that the proteins of bovine pancreatic juice and pancreatic zymogen granules contain identical concentrations of a ribonuclease that on chromatography over Amberlite IRC-50 exhibits the behavior of the enzyme previously called (2, 3) ribonuclease B. The present report deals with the isolation of ribonuclease B from bovine pancreatic juice and provides a description of some of i...

The elevated ribonuclease activity produced in the endosperm of a maize (Zea mays L.) inbred, W64A, by homozygous opaque-2, results from a more than doubled rate of ribonuclease accumulation occurring prior to 16 days post-pollination; after 16 days the rates in opaque-2 and normal are the same, suggesting that opaque-2 is no longer active. The pattern of ribonuclease increase in the opaque-2 d...

Ribonuclease H (RNA.DNA-hybrid ribonucleotidohydrolase, EC 3.1.4.34) has been reported to copurify with reverse transcriptase (RNA directed DNA polymerase) of RNA tumor viruses. In addition, viral specific ribonuclease H and reverse transcriptase of avian type-C viruses are thought to be part of the same polypeptide. In this report we show that a fraction of the ribonuclease H activity from Rau...

In an earlier investigation from this laboratory (I), prostatic phosphomonoesterase was used for the partition of the phosphomonoester and phosphodiester groups in ribonuclease digests. It was shown that the inorganic phosphate formed during incubation of ribonuclease digests with phosphatase originated practically exclusively from the acid-stable (pyrimidine) nucleotide groups of ribonucleic a...