Open AccessPhenylalanyl‐tRNA, Lysyl‐tRNA, Isoleucyl‐tRNA and Arginyl‐tRNA Synthetases
Author(s) -
FREIST Wolfgang,
CRAMER Friedrich
Publication year - 1980
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1980.tb04622.x
Subject(s) - aminoacylation , transfer rna , biochemistry , aminoacyl trna synthetase , enzyme , chemistry , ribose , stereochemistry , moiety , rna , biology , gene
Ten analogs of ATP have been tested in the ATP/PP i exchange reaction of Phenylalanyl‐tRNA, lysyl‐tRNA, isoleucyl‐tRNA and arginyl‐tRNA synthetases from baker's yeast. Three compounds are substrates for Phenylalanyl‐tRNA, seven for lysyl‐tRNA, two for isoleucyl‐tRNA and five for arginyl‐tRNA synthetase. Their K m and V values have been determined. No analog was an inhibitor. (3′‐dATP), 3′‐Deoxyadenosine 5′‐triphosphate which is an inhibitor of the four enzymes in the aminoacylation reaction, becomes a good substrate in the PP i exchange. Additionally lysyl‐tRNA synthetase accepts two analogs with modifications at position 6 of the purine and three analogs modified at the ribose moiety as substrates in the PP i exchange, whereas these compounds are inactive or inhibitors in the aminoacylation reaction. In general the enzymes are less specific in the ATP/PP i exchange and the results indicate a more sophisticated proof of the nucleotide moiety upon aminoacylation. This could occur with the amino‐acyladenylate intermediate as well as with any other intermediate.