Open AccessCharacterization of the Native and Denatured Conformations of tRNA Ser and tRNA Phe from Yeast
Author(s) -
Streeck Rolf E.,
Zachau Hans G.
Publication year - 1972
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1972.tb02109.x
Subject(s) - transfer rna , denaturation (fissile materials) , chemistry , crystallography , hyperchromicity , yeast , biochemistry , stereochemistry , rna , dna , gene , nuclear chemistry
Previous work on the partial digestion of the native and denatured forms of tRNA Ser and tRNA Phe from yeast with T1‐RNAase was extended. Detailed studies with pancreatic and T2‐RNAase and a few experiments with sheep kidney nuclease and acid RNAase from hog spleen revealed characteristically different fragmentation patterns for the native and denatured forms of the tRNAs. Apparently it is mainly the miniloop and dihydrouridine regions which are involved in the conformational changes responsible for denaturation. The rate constants, activation enthalpies, and activation entropies of the renaturation process were calculated from amino acid acceptance data. When the changes in hyperchromicity at 260 nm of the denatured tRNAs were followed as a function of time, a process was detected which in tRNA Phe is 5–10 times and in tRNA ser 10–20 times faster than the renaturation as measured by acceptor activity. The whole net change in absorption, possibly representing the total net change in base stacking, occurs during the fast, process. The activation enthalpies and activation entropies are different for the fast and the over‐all processes.