Published on None in volume None.

PubMed ID: 7735833

DOI: 10.1016/s0969-2126(01)00147-2

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 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.