One of the key results of that data obtained from the paper allows a mechanism of autoinhibitory regulation to be proposed, autoinhibition allows the interactions within a protein to regulate the protein function which in DNMT1 occurs at unmethylated CpG sites on DNA: 'Unmethylated DNA is excluded from the active site of mDNMT1 by the binding of the CXXC domain, whereas the presence of the acidic autoinhibitory CXXC-BAH1 linker positioned directly between the DNA and the active site prevents entrance of DNA into the catalytic pocket.
The Autoinhibitory Linker
The Autoinhibitory Linker (Green) Viewed Between CXXC (Red) and BAH1 Domain (Blue)
Though this image above shows each domain, it doesn't really give a great grasp of the autoinhibition in terms of the of the whole enzyme so a more interesting view is provided below with the mDMNT1-DNA complex:
CXXC (Red), Linker (Pink) and BAH1 (Blue)
As you can see the linker clearly interacts with the DNA and therefore a method of autoinhibition can be proposed (as described above).
The paper also proposes 'that unmethylated CpG sites are protected from de novo methylation through binding by the CXXC domain as CpG dinucleotides emerge from the replication complex' which originated from work by H. Leonhardt et al (1992) showing that maintanience methylation is tightly coupled to DNA replication.
The key result of this proposition means that the efficiency of the maintainence of methylation through inhibition increases in de novo methylation.
