histone-lysine N-methyltransferase, H3 lysine-9 specific SUVH4-like protein;(source:Araport11)
Encodes a histone 3 lysine 9 specific methyltransferase involved in the maintenance of DNA methylation. SUVH4/KYP is a SU(VAR)3-9 homolog, a SET domain protein. Known SET domain proteins are involved in epigenetic control of gene expression. There are 10 SUVH genes in Arabidopsis and members of this subfamily of the SET proteins have an additional conserved SRA domain. In kyp mutants, there is a loss of CpNpG methylation. The protein was shown to bind to methylated cytosines of CG, CNG and CNN motifs via its SRA domain but has a preference for the latter two. There is also evidence that KYP/SUVH4 might be involved in the telomerase-independent process known as Alternative Lengthening of Telomeres.
Protein associated with the U5 snRNP, during its maturation and its post-splicing recycling and which is required for spliceosomal tri-snRNP complex assembly in the nucleus. Has a molecular sequestering activity and transiently hinders SNRNP200 binding sites for constitutive splicing factors that intervene later during the assembly of the spliceosome and splicing. Together with its molecular sequestering activity, may also function as a molecular adapter and placeholder, coordinating the assembly of the U5 snRNP and its association with the U4/U6 di-snRNP.