Open AccessProbing the environment of lanthanide binding sites in yeast tRNA Phe by specific metal‐ion‐promoted cleavages
Author(s) -
CIESIOŁKA Jerzy,
MARCINIEC Tadeusz,
KRZYŻOSIAK Wlodzimierz J.
Publication year - 1989
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1989.tb14851.x
Subject(s) - europium , lanthanide , transfer rna , chemistry , yeast , intramolecular force , cleavage (geology) , hydrolysis , binding site , crystallography , inorganic chemistry , ion , stereochemistry , biochemistry , rna , biology , organic chemistry , paleontology , fracture (geology) , gene
Specific yeast tRNA Phe hydrolysis brought about by europium ions has been studied in detail using the 32 P‐end‐labeled tRNA and polyacrylamide gel electrophoresis. The dependence of the induced cleavages on pH, temperature and concentration of the europium ions has been determined. Europium hydrolyzes yeast tRNA Phe in the D‐loop at phosphates 16 and 18, and the anticodon loop of phosphates 34 and 36. The two D‐loop cuts are thought to take place from two distinct europium binding sites, while the two anticodon loop cleavages from a single site. Eight other members of the lanthanide series and ytrium give basically the same pattern of cleavages as europium. The specific cleavages taking place in the anticodon loop occur in an intramolecular mode from the lanthanide binding site that has not been found in yeast tRNA Phe crystal structure. It appears from the comparison of the europium‐promoted cuts with those generated by magnesium and lead that the former two ions give more similar but not identical cleavage patterns. The usefulness of the specific cleavages induced by lanthanides for probing their own and magnesium binding sites in tRNA is discussed.