1. ATP Hydrolysis by the SNF2 Domain of Dnmt5 Is Coupled to Both Specific Recognition and Modification of Hemimethylated DNA
- Author
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Dumesic, Phillip A, Stoddard, Caitlin I, Catania, Sandra, Narlikar, Geeta J, and Madhani, Hiten D
- Subjects
Biochemistry and Cell Biology ,Biological Sciences ,Genetics ,Adenosine Triphosphatases ,Adenosine Triphosphate ,Cryptococcus neoformans ,DNA (Cytosine-5-)-Methyltransferases ,DNA Methylation ,DNA ,Fungal ,Fungal Proteins ,Hydrolysis ,Nucleosomes ,Saccharomyces cerevisiae ,Saccharomyces cerevisiae Proteins ,Substrate Specificity ,Transcription Factors ,ATPase ,DNA methylation ,DNA methyltransferase ,Dnmt5 ,SNF2 ,enzyme mechanism ,enzyme specificity ,epigenetics ,maintenance methylation ,Medical and Health Sciences ,Developmental Biology ,Biological sciences ,Biomedical and clinical sciences ,Health sciences - Abstract
C.neoformans Dnmt5 is an unusually specific maintenance-type CpG methyltransferase (DNMT) that mediates long-term epigenome evolution. It harbors a DNMT domain and SNF2 ATPase domain. We find that the SNF2 domain couples substrate specificity to an ATPase step essential for DNA methylation. Coupling occurs independent of nucleosomes. Hemimethylated DNA preferentially stimulates ATPase activity, and mutating Dnmt5's ATP-binding pocket disproportionately reduces ATPase stimulation by hemimethylated versus unmethylated substrates. Engineered DNA substrates that stabilize a reaction intermediate by mimicking a "flipped-out" conformation of the target cytosine bypass the SNF2 domain's requirement for hemimethylation. This result implies that ATP hydrolysis by the SNF2 domain is coupled to the DNMT domain conformational changes induced by preferred substrates. These findings establish a new role for a SNF2 ATPase: controlling an adjoined enzymatic domain's substrate recognition and catalysis. We speculate that this coupling contributes to the exquisite specificity of Dnmt5 via mechanisms related to kinetic proofreading.
- Published
- 2020