FIG 6 .

Comparison of the GlnH ligand binding pocket with other amino acid binding proteins. (A) Alignment of GlnH with solute-binding proteins in the PDB showed that the residues whose side chains make polar contact with the R group of the Asp ligand are unique to Asp/Gly-specific solute-binding proteins (highlighted in green), while the residues that contact other parts of the ligand are conserved in solute-binding proteins specific for diverse amino acids. (Side-chain-mediated polar contacts are highlighted in cyan, and residues making hydrophobic or main chain contacts are highlighted in yellow.) Mtb, M. tuberculosis; Cgl, C. glutamicum. (B) Alignment of SBPs encoded with homologues of PknG allowed a prediction of those that are likely to be specific for Asp/Glu (starred).