title: Peptidyl transfer ribonucleic acid hydrolase activity of proteinase k.
abstract: Proteinase k, a seryl-protease obtained from Tritirachium album, is able to specifically hydrolyze N-blocked aminoacyl transfer ribonucleic acids (tRNAs). The blocked amino acid is released, and the tRNA molecule remains able to be recharged by its cogante amino acid. Aminoacyl-tRNAs are highly resistant to hydrolysis by the protease. This activity is not due to contamination of the protease preparation. A commercial protease from Streptomyces griseus displayed a similar activity, while trypsin, chymotrypsin, and papain unspecifically hydrolyzed all charged tRNAs tested. The characteristics of the hydrolysis performed by proteinase k closely resemble the peptidyl-tRNA hydrolase activity described in different cells as a scavenger for the peptidyl-tRNA that eventually falls from the polysomes. Out results warn about a hasty identification of any N-blocked aminoacyl-tRNA hydrolase activity in the cytoplasm as an independent peptidyl-tRNA hydrolase.
mesh_terms: D010450:Endopeptidases / Q000378:metabolism*; D004926:Escherichia coli; D006867:Hydrolases / Q000378:metabolism*; D007700:Kinetics; D003904:Mitosporic Fungi / Q000201:enzymology; D010664:Phenylmethylsulfonyl Fluoride / Q000494:pharmacology; D012346:RNA, Transfer, Amino Acyl; D012441:Saccharomyces cerevisiae; D012694:Serine; D013696:Temperature
chemical_list: D012346:RNA, Transfer, Amino Acyl; D012694:Serine; D010664:Phenylmethylsulfonyl Fluoride; D006867:Hydrolases; D010450:Endopeptidases