... Pro155, the main-chain amide groups of Ile128 and Arg129.Despite these differences in the coordination of the res-idues in the tip, the fold of the loop is strikingly simi-lar. The rmsd for the ... and the active-site resi-dues are identical, except for two residues in the ATP-binding site. We describe, in detail, the binding modes of the methionine, the adenosine and the residuesinvolved. ... the KMSKS domain in yellow and the anticodon domain in blue. The intervening helices a2 and a8 in the catalytic domain are coloredcyan. The linking p-helix a13 between the KMSKS domain and the anticodon...