Interaction of eukaryotic tyrosyl-tRNA-synthetase with high molecular weight RNA
Kurochkin, I.V.; Korneliuk, A.I.; Matsuka, G.Kh.
Molekuliarnaia Biologiia 25(3): 779-786
1991
ISSN/ISBN: 0026-8984 PMID: 1944260 Document Number: 372889
The affinity of eukaryotic tyrosyl-tRNA synthetases from bovine liver and from yeast for Escherichia coli ribosomal RNA and synthetic polyribonucleotides has been studied by protein binding on the tRNA-Sepharose column and enzyme inhibition by high molecular weight RNAs. Tyrosyl-tRNA synthetase from bovine liver (Mr2.59kDa) was fully retained on the rRNA-Sepharose and eluted by buffer with 100 mM KCl. The functionally active modified form of bovine liver tyrosyl-tRNA synthetase obtained by endogenous limited proteolysis (Mr2.38 kDa) partially maintains the affinity for rRNA and is eluted by 50mM KCl. The highest rRNA-binding ability was revealed for yeast tyrosyl-tRNA synthetase eluted by 200 mM KCl. The E. coli tyrosyl-tRNA synthetase was not retained on rRNA-Sepharose. The aminoacylation activities of both bovine liver and yeast tyrosyl-tRNA synthetases were efficiently inhibited by rRNA and the inhibition was partially competitive in respect to tRNATyr. At the same time the activities of proteolytically modified bovine tyrosyl-tRNA synthetase and E. coli tyrosyl-tRNA synthetase were not influenced by the addition of rRNA. Synthetic single-and double-stranded polyuribonucleotides specifically inhibited the activity of bovine tyrosyl-tRNA synthetase to different extent. The inhibition degree of bovine liver tyrosyl-tRNA synthetase decreased in the order:poly (G)>poly(I)>poly(I).cntdot.poly(C)>poly(G).cntdot.poly(C)>poly(C)>poly(A). Poly (U) did not inhibit the activity of bovine liver tyrosyl-tRNA synthetase.