Structural studies of lysyl-tRNA synthetase: conformational changes induced by substrate binding.

S. Onesti (1) , G. Desogus (1) , A. Brevet (2) , Jie Chen (2) , Sylvain Blanquet (2) , Pierre Plateau (2) , P. Brick (1)

1 Biophysics Section
2 BIOC - Laboratoire de Biochimie de l'Ecole polytechnique

Lysyl-tRNA synthetase is a member of the class II aminoacyl-tRNA synthetases and catalyses the specific aminoacylation of tRNA(Lys). The crystal structure of the constitutive lysyl-tRNA synthetase (LysS) from Escherichia coli has been determined to 2.7 A resolution in the unliganded form and in a complex with the lysine substrate. A comparison between the unliganded and lysine-bound structures reveals major conformational changes upon lysine binding. The lysine substrate is involved in a network of hydrogen bonds. Two of these interactions, one between the alpha-amino group and the carbonyl oxygen of Gly 216 and the other between the carboxylate group and the side chain of Arg 262, trigger a subtle and complicated reorganization of the active site, involving the ordering of two loops (residues 215-217 and 444-455), a change in conformation of residues 393-409, and a rotation of a 4-helix bundle domain (located between motif 2 and 3) by 10 degrees. The result of these changes is a closing up of the active site upon lysine binding.

Domaines: Biochimie, Biologie Moléculaire

S. Onesti, G. Desogus, A. Brevet, Jie Chen, Sylvain Blanquet, et al.. Structural studies of lysyl-tRNA synthetase: conformational changes induced by substrate binding.. Biochemistry, 2000, 39 (42), pp.12853-61. ⟨10.1021/bi001487r⟩. ⟨hal-00771811⟩