Dramatic variations in the alignment between a Glutaminyl-tRNA synthetase (1qtq) and a Caspase-8 (1qtn). For 1qtq, the flexible alignment regions contain two PKC phosphorylation sites ('SKR' and 'TDK') in a helix and a myristoylation site ('GNKWCI') in a coil region. (A) The 'master-slave' alignments with 1qtn as master, secondary structures at the top (1qtn) and the bottom (1qtq), functional sites marked in apposite windows. (B) The different Glutaminyl-tRNA synthetase and Caspase-8 structures with 1qtq and alternatives in orange and 1qtn and alternatives in blue. Functional motifs are marked. Image rendered using SwissPDBViewer  and PovRay .