Original scientific paper

Nucleases in Yeast Acting on the 3'-Terminus of Transfer Ribonucleic Acid

N. Franjić ; Department of Organic Chemistry and Biochemistry, Ruder Boskovic Institute, Bijenicka 54, 41000 Zagreb, Croatia, Yugoslavia
Ž. Kućan ; Department of Organic Chemistry and Biochemistry, Ruder Boskovic Institute, Bijenicka 54, 41000 Zagreb, Croatia, Yugoslavia

Abstract

Two enzymes capable of hydrolytic removal of 3'-terminal
adenosine from specifically labeled tRNA were identified in yeast.
One of them was highly purified by chromatography on phosphocellulose.
It acts on the 3'-terminus of tRNA by removing free
adenosine, followed by 2'- (or 3'-) cytidylic acid; it also hydrolyses
dinucleoside monophosphates, viral and ribosomal RNA, but it is
inactive against either native or denatured DNA. Hence, the
enzyme is a ribonucleate 3'-nucleotidohydrolase, and may be
identical to previously described »ribosomal« ribonuclease of yeast.
The other enzyme is a labile acidic protein, with M. W. around
31000. It removes the 3'-terminal adenosine of tRNA as adenosine-
5'-monophosphate in a reaction with a pH optimum of 7.2, which
is not inhibited by Mgrt. Chemical and photochemical modification
of tRNA increases its susceptibility to the enzyme. In conjunction
with tRNA adenylyl (cytidylyl) transferase, the enzyme may be
responsible for the turnover of 3'-terminal adenylic acid in yeast.

Keywords

Hrčak ID:

195865

URI

https://hrcak.srce.hr/195865

Publication date:

1.3.1980.

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