N-acetylphenylalanyl-tRNA hydrolase from yeast. Purification and properties.
This paper describes the purification and properties of an enzyme present in yeast which splits N-acetylphenylalanyl-tRNA to N-acetylphenylalanine and tRNA. The enzyme has been 35000 as estimated by filtration  on Sephadex G-150, is maximally active in the presence of a divalent cation (Mg2+ , Mn2+ or Ca2+) and has a pH optimum at around neutrality. The enzyme is highly specific in hydrolyzing N-acetylphenylalanyl-tRNA (Km = 0.4 micron). Phenylalanyl-tRNA is hydrolyzed with a similar apparent affinity but with an efficiency of 40% of that found for N-acetylphenylalanyl-tRNA. Other free or N-substituted aminoacyl-tRNAs are not substrates of this hydrolase. Neither of the two reaction products are effective inhibitors of this enzyme. Based on its substrate specificity, the trivial name of N-acetylphenylalanyl-tRNA hydrolase is proposed for this enzyme.
D002265:Carboxylic Ester Hydrolases / Q000302:isolation & purification / Q000378:metabolism*; D002413:Cations, Divalent / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D008274:Magnesium / Q000494:pharmacology; D008970:Molecular Weight; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism; D012440:Saccharomyces / Q000201:enzymology*; D013347:Subcellular Fractions / Q000201:enzymology; D013379:Substrate Specificity
D002413:Cations, Divalent; D012346:RNA, Transfer, Amino Acyl; D002265:Carboxylic Ester Hydrolases; C018734:N-acetylphenylalanyl-tRNA hydrolase; D008274:Magnesium