Primary Citation of Related Structures:   1LYL
PubMed Abstract: 
Lysyl-tRNA synthetase catalyzes the attachment of the amino acid lysine to the cognate tRNA. The enzyme is a member of the class II amino-acyl-tRNA synthetases; the crystal structures of the seryl- and aspartyl-tRNA synthetases from this class are already known ...
Lysyl-tRNA synthetase catalyzes the attachment of the amino acid lysine to the cognate tRNA. The enzyme is a member of the class II amino-acyl-tRNA synthetases; the crystal structures of the seryl- and aspartyl-tRNA synthetases from this class are already known. Lysyl-tRNA synthetase shows extensive sequence homology with aspartyl-tRNA synthetase. In Escherichia coli there are two isoforms of the enzyme, LysS and LysU. Unlike LysS, which is synthesized under normal growth conditions, LysU is the product of a normally silent gene which is overexpressed under extreme physiological conditions (such as heat-shock), and can synthesize a number of adenyl dinucleotides (in particular AppppA). These dinucleotides have been proposed to act as modulators of the heat-shock response and stress response.
Related Citations: 
Crystallization and Preliminary Diffraction Studies of E.Coli Lysyl-T(Slash)RNA Synthetase (Lysu) Onesti, S., Theoclitou, M.-E., Wittung, E.P.L., Miller, A.D., Plateau, P., Blanquet, S., Brick, P. (1994) J Mol Biol 243: 123