Biopolymers and cell. 2000; 16 (6): 515 - 524

Structure modeling of the COOH-terminal cytokine-like module of the mammalian cytoplasmic tyrosyl-tRNA synthetase

A C. Golub, K. A. Odynets, A. Yu. Nyporko, A. I. Konelyuk

COOH-terminal module ('-module) of cytoplasmic tyrosyl-tRNA synthetases from chordate and insects is homologous to the mammalian cytokine EMAP II (52.7 % identity) and in free form has similar biological properties in experiments in vitro. The main part of C-module is a domain with «OB-fold» type of structure (B-domain, residues Val363-Lys470), containing five fi-strands, which are characteristic for this fold type. Like some other «OB-fold»-containing domains C-module has affinity to nucleic acids. By using comparative homology modeling methods the C-module structure model of bovine (Bos taurus) tyrosyl-tRNA synthetase is created. The comparison of C-module model with anticodon-binding domains of aspartyl- and lysyl-tRNA synthetases allows to predict the interacting surface with RNA and some functionally important amino acid residues. The C-module structure model will help to study further the tyrosyl-tRNA synthetase structure and functions, its interaction with tRNATyr, and cytokine-like properties of the free C-module.