Backbone Brackets and Arginine Tweezers delineate Class I and Class II aminoacyl tRNA synthetases
Fig 5
Protein-ligand contacts in representative adenosine phosphate-binding complexes for aaRS Class I and Class II.
Residues are grouped according to the non-amino acid ligand fragment (phosphate, ribose, or adenine) that they are interacting with. Preferred interaction types for each aaRS Type and binding site residue are color-coded. Fields split into two triangles indicate two equally preferred interactions. The asterisk (*) indicates aaRS Types incorporating noncanonical amino acids. Automatically retrieved [77, 78] mutation effects [79–85] are shown as centered shapes. In essence, Class I interactions are mainly hydrogen bonds, while Class II adenosine phosphate-binding is realized by an array of different interaction types. All sequence numbers are given according to the MSA.