NlaIII digestion of representative Kanr ColE1-like plasmids. Plasmid DNAs were digested with NlaIII for 2 h and separated on 2% TAE-agarose 3:1/140 V·h. Gel was then stained with GelRed for 1 h and photographed. Lanes from left to right: 100-bp ladder, group C3 (ARS#574), group C2 (ARS#886), group C (ARS#852), group B2 (ARS#936), group B (ARS#550), group A2 (ARS#518), group A (ARS#688), and 100-bp ladder. The difference between B and B2 is marked by an asterisk.