Exhibits ATPase activity. Binds DNA/RNA in a non-specific manner and exhibits endonuclease activity. Probably involved in DNA repair. Involved in RNA-directed DNA methylation (RdDM) as a component of the RdDM machinery and required for gene silencing. May also be involved in the regulation of chromatin architecture to maintain gene silencing. Together with MORC4, acts to suppress a wide set of non-methylated protein-coding genes, especially involved in pathogen response. Positive regulators of defense against the oomycete Hyaloperonospora arabidopsidis (Hpa) (PubMed:27171361). Homodimer and heterodimer. Component of an RNA-directed DNA methylation (RdDM) complex. Forms homomeric complexes (PubMed:27171361). Accumulates in discrete nuclear bodies adjacent to chromocenters. The double mutant atmorc4 atmorc7 exhibits a pathogen response phenotype with abnormal up-regulation of several genes involved in plant defense. Belongs to the MORC ATPase protein family.