Open AccessOn the Stereochemistry of Activation of Phenylalanine by Phenylalanyl‐tRNA Synthetase from Baker's Yeast
Author(s) -
HAAR Friedrich,
CRAMER Friedrich,
ECKSTEIN Fritz,
STAHL KurtWilhelm
Publication year - 1977
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1977.tb11591.x
Subject(s) - transfer rna , diastereomer , stereochemistry , substrate (aquarium) , phenylalanine , chemistry , substrate specificity , aminoacyl trna synthetase , enzyme , yeast , amino acyl trna synthetases , biochemistry , biology , rna , amino acid , gene , ecology
Because of its chiralic α‐phosphorus atom adenosine 5′‐ O ‐(1‐thiotriphosphate) (ATPαS) exists in two diastereomeric forms, arbitrarily named (A) and (B). For phenylalanyl‐tRNA synthetase ATPαS (A) is a substrate whereas ATPαS (B) is neither a substrate nor an inhibitor. During the ATPαS (A)/PP i exchange reaction with phenylalanyl‐tRNA synthetase the configuration at the α‐phosphorus atom is retained. The mechanistic implications of these findings are discussed. Preliminary investigations with several other aminoacyl‐tRNA synthetases show that the stereochemical requirement with respect to the α‐phosphorus of ATP is not identical for all aminoacyl‐tRNA synthetases.