Binding site sharing in Type II restriction–modification systems is unclear

Determine whether Type II restriction endonucleases and their corresponding methyltransferases share the same DNA binding site in restriction–modification systems.

Background

While discussing restriction–modification systems, the authors note that types I, III, and IIG have endonucleases and methyltransferases that share the same DNA binding site, cutting outside it. They contrast this with Type II systems, for which the binding site relationship is uncertain.

Clarifying this structural and functional relationship in Type II systems would refine understanding of enzymatic coordination and potential information-processing roles in DNA.

References

Except for Type II restriction endonucleases (where it is still unclear whether the endonuclease and methyltransferase share the same binding site), the other three types of restriction endonucleases and methyltransferases share the same DNA binding site but cut outside it.

— DNA and Human Language: Epigenetic Memory and Redundancy in Linear Sequence (2503.23494 - Yang et al., 30 Mar 2025) in Discussion and conclusion