Open AccessModification of amino groups in EF‐Tu · GTP and the ternary complex EF‐Tu · GTP · valyl‐tRNA Val
Author(s) -
ANTONSSON Bruno,
LEBERMAN Reuben
Publication year - 1984
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1984.tb08218.x
Subject(s) - ternary complex , gtp' , lysine , reactivity (psychology) , chemistry , ternary operation , stereochemistry , nucleic acid , ef tu , aspartic acid , amino acid , biochemistry , rna , transfer rna , enzyme , medicine , alternative medicine , pathology , computer science , programming language , gene
In an attempt to describe the binding region of EF‐Tu · GTP for aminoacyl‐tRNA, the ɛ‐amino groups of the lysine residues of the protein molecule in the GTP and ternary complexes were modified with ethyl acetimidate. Using [ 14 C]ethyl acetimidate, tryptic digestion, fractionation of peptides by high‐performance liquid chromatography, and amino acid analysis, all reactive lysine residues could be unambiguously identified 19 of the 23 lysine residues of EF‐Tu were labelled under conditions for ternary complex stability. Of these only 8 showed differences in reactivity between free and complexed EF‐Tu · GTP. In the ternary complex lysine residues 208 and 390 [Jones, M. D., Petersen, T. E., Nielsen, K. M., Magnusson, S., Sotterup‐Jensen, L., Gausing, K. and Clark, B. F. C. (1980) Eur. J. Biochem. 108 , 507–526] showed an increase in reactivity (60% and 30% respectively) and residues 2, 4, 237, 248, 263, and 282 showed a decrease in reactivity (between 85% and 37%) compared to the values observed with EF‐Tu · GTP. The greatest changes in reactivity were observed for lysine residues 2, 4 and 263. These data can be combined with the available structural information to identify possible areas of contact between the protein and nucleic acid moieties in the ternary complex.