Premium
Two isomorphous heavy‐atom derivatives of crystalline methionyl‐tRNA synthetase from Escherichia coli
Author(s) -
Monteilhet Claude,
Zelwer Charles,
Risler Jean-Loup
Publication year - 1974
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(74)80344-3
Subject(s) - escherichia coli , citation , chemistry , stereochemistry , crystallography , physics , gene , library science , biochemistry , computer science
Aminoacyl-tRNA synthetases play a key role in the biosynthesis of proteins by their ability to specifically recognize an amino acid and its corresponding tRNA. An understanding of the basis of such specific proteinnucleic acid recognition requires the knowledge of the structure of the molecules involved. This goal is probably not very remote now since a high resolution model of yeast phenylalanine tRNA has been obtained recently [l] , while four aminoacyl-tRNA synthetases have been obtained in a crystalline form [2-61 and are the object of crystallographic studies. In this paper we report on the preparation of two heavy-atom derivatives of crystalline methionyl-tRNA synthetase from E.coZi. The crystallized protein, a single polypeptide chain of molecular weight 65 000 [7,8], is a fully active fragment obtained by proteolysis of the native enzyme [4,7]. The great similarities between the catalytic properties of native methionyl-tRNA synthetase and its tryptic fragment, as evidenced by a number of recent experiments [9-121, indicate that the latter is a fully representative model of the native enzyme. Crystals are monoclinic, space-group F’2 1 , and contain one molecule per asymmetric unit [4] .