Recognition sequence-like sites in the restriction enzymes: Multiple Sequence Alignment (MSA) of 12 REs (PstI isoschizomers) and their common RS. The protein sequences of the enzymes and the overlappingly translated sequences (OTS) of the RS direct (Dir, D) and reverse (Rev, R) readings were compared. The first alignment includes all 14 sequences (colored by conservation) while the other 12 alignments indicate individual comparisons of the enzymes to their common RS (colored by conservation). The section of the alignments seen corresponds to the entire protein sequence (326 amino acids) of PstI. The vertical lines between the alignments indicate the conserved residues which align to the direct (red) and reverse (green) readings of the RS.