N-terminal Xaa-Pro-Lys N-methyltransferase 1-B
Distributive alpha-N-methyltransferase that methylates the N-terminus of target proteins containing the N-terminal motif [Ala/Gly/Pro/Ser]-Pro-Lys when the initiator Met is cleaved. Specifically catalyzes mono-, di- or tri-methylation of the exposed alpha-amino group of the Ala, Gly or Ser residue in the [Ala/Gly/Ser]-Pro-Lys motif and mono- or di-methylation of Pro in the Pro-Pro-Lys motif. Required during mitosis for normal bipolar spindle formation and chromosome segregation via its action on target proteins.
Belongs to the methyltransferase superfamily. NTM1 family.