-3 cat sequence_file | sed "y/atgc/tacg/" | rev | sed "s/^..//g" | sed "s/.../& /g" | sed "s/t/u/g" | sed -f genetic-code.sed | -3 cat sequence_file | sed "y/atgc/tacg/" | rev | sed "s/^..//g" | sed "s/.../& /g" | sed "s/t/u/g" | sed -f genetic-code.sed |