Isoschizomers are restriction enzyme pairs that recognize the same recognition sequence.
The prototype is the first enzyme discovered that recognizes a specific sequence; all subsequent enzymes that recognize that sequence are isoschizomers.
Isoschizomers can be isolated from a variety of bacteria strains, which means they may require varied reaction conditions.
For example, SphI (CGTAC/G) and BbuI (CGTAC/G) are isoschizomers of one other.