Graphical view of cysteinyl-tRNA synthetase with extremophilic protein adaptations. The homology models of Halobacterium salinarum (Hs), Pyrococcus furiosus (Pf), and Methanolobus psychrophilus (Mp) CysRS were generated based on the structure of Escherichia coli CysRS (see text for details). In the upper corner, the crystal structure of the Ec CysRS (PDB 1U0B, [10]) is provided for orientation and description of the enzyme’s features. (a) and (c) Coulombic surface map of the models on the tRNA side and back of the molecule, respectively. The Coulombic surface maps the amino acid electrostatic potential (according to Coulomb’s law) on surface residues: red is a negative potential, blue is a positive potential, and white indicates a relatively nonpolar potential. (b) and (d) The conserved features (in green) and unique adaptations highlighted on the surface of the models on the tRNA side and back of the molecule, respectively. The corresponding adaptations have been noted in the sequence alignment in Figure S1 (See Figure S1 in the Supplementary Material available online at http://dx.doi.org/10.1155/2013/373275). Unique features are highlighted in different colors for the different extremes: halophilic adaptations are in pink, the thermophilic adaptations are in red, and the psychrophile adaptations are in blue. The molecular graphics were created with the USCF Chimera package [11].
