Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.4.1 (phosphodiesterase)
 18,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two ribonucleases H (RNases H) were purified to apparent homogeneity from the yeast Saccharomyces cerevisiae. The enzymes were separated from the previously described yeast ribonuclease H (RNase H(70), Karwan, R., Blutsch, H., and Wintersberger, U. (1983) Biochemistry 22, 5500-5507) by chromatography on Mono Q and blue-Sepharose columns and from each other on a Mono S column. The two proteins, RNase H(55) of molecular weight around 55,000 and RNase H(42) of molecular weight around 42,000, exhibit distinct enzymatic properties: RNase H(55) acts as a 5'-exonuclease of low specific activity and produces predominantly monoribonucleotides from the synthetic hybrid poly(rA)-poly(dT). RNase H(42) efficiently releases oligoribonucleotides from the same substrate. Polyclonal antibodies against these proteins do not cross-react with RNase H(70), and thus, these two RNases H probably do not represent proteolytic breakdown products of RNase H(70). Peptide maps obtained by total digestion of RNase H(55) and RNase H(42) with trypsin reveal several common peptides and, therefore, suggest that the two enzymes are related to each other. We tentatively conclude that RNase H(55) is proteolytically processed to RNase H(42) in vivo.
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PMID:In addition to RNase H(70) two other proteins of Saccharomyces cerevisiae exhibit ribonuclease H activity. 304 96

A ribonuclease (RNAase; EC 3.1.14.1) from brewer's yeast was purified 90-fold. Crude RNAase was initially separated from other proteins by precipitation at pH 4.0 after incubation of the mechanically disrupted yeast cells at pH 6.0 and 52 degrees C for 30 min. The RNAase was purified from the supernatant by ultrafiltration with a PM-30 membrane and adsorption chromatography on hydroxyapatite. RNAase preparation was free of phosphatase, deoxyribonuclease and phosphodiesterase activities. It showed maximum activity at pH 6.0 and a temperature optimum of 52 degrees C with yeast RNA as substrate. This RNAase hydrolysed yeast RNA to nucleoside 3'-phosphates and showed no evidence of base specificity.
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PMID:A rapid method for the isolation of ribonuclease from yeast (Saccharomyces carlsbergensis). 700 98