label: C-terminal L-alpha-aminoacyl-L-glutamyl-[tubulin] + L-glutamate => C-terminal L-alpha-aminoacyl-L-glutamyl-L-glutamyl-[tubulin] + H2O
label_lc: c-terminal l-alpha-aminoacyl-l-glutamyl-[tubulin] + l-glutamate => c-terminal l-alpha-aminoacyl-l-glutamyl-l-glutamyl-[tubulin] + h2o