Probable regulatory subunit of the N6-methyltransferase complex, a multiprotein complex that mediates N6-methyladenosine (m6A) methylation at the 5'-[AG]GAC-3' consensus sites of some mRNAs (PubMed:15047892, PubMed:28503769). Associates with MTA, MTB, VIR and HAKAI to form the m6A writer complex which is essential for adenosine methylation at specific mRNA sequences (PubMed:28503769). N6-methyladenosine (m6A) plays a role in mRNA stability, processing, translation efficiency and editing (PubMed:15047892, PubMed:28503769). Essential protein required during endosperm development and embryogenesis. Involved in endoreduplication, especially in trichomes. May play a role in splicing events (PubMed:15047892). Forms homodimers (PubMed:28503769). Interacts with MTA/EMB1706 (PubMed:18505803, PubMed:28503769). Interacts with FKBP12; interaction is inhibited by the immunosuppressive drug FK506 (PubMed:9807817). Interacts with VIR (PubMed:28503769). Associates with MTA, MTB, VIR and HAKAI to form the m6A writer complex which is essential for adenosine methylation at specific mRNA sequences (PubMed:28503769). Nuclear with a speckled distribution pattern. Ubiquitously expressed with higher levels in primary and lateral roots, leaves, trichomes, and in pollen grains (at protein level). Embryogenesis arrest at the midglobular stage. Belongs to the fl(2)d family.