title: Crystal structure of the N-terminal methyltransferase-like domain of anamorsin.
abstract: Anamorsin is a recently identified molecule that inhibits apoptosis during hematopoiesis. It contains an N-terminal methyltransferase-like domain and a C-terminal Fe-S cluster motif. Not much is known about the function of the protein. To better understand the function of anamorsin, we have solved the crystal structure of the N-terminal domain at 1.8 Å resolution. Although the overall structure resembles a typical S-adenosylmethionine (SAM) dependent methyltransferase fold, it lacks one α-helix and one β-strand. As a result, the N-terminal domain as well as the full-length anamorsin did not show S-adenosyl-L-methionine (AdoMet) dependent methyltransferase activity. Structural comparisons with known AdoMet dependent methyltransferases reveals subtle differences in the SAM binding pocket that preclude the N-terminal domain from binding to AdoMet. The N-terminal methyltransferase-like domain of anamorsin probably functions as a structural scaffold to inhibit methyl transfers by out-competing other AdoMet dependant methyltransferases or acts as bait for protein-protein interactions.
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
authors.forename: Gaojie
authors.initials: G
authors.lastname: Song
authors.forename: Chongyun
authors.initials: C
authors.lastname: Cheng
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
authors.forename: Neil
authors.initials: N
authors.lastname: Shaw
authors.forename: Zhi-Cheng
authors.initials: ZC
authors.lastname: Xiao
authors.forename: Zhi-Jie
authors.initials: ZJ
authors.lastname: Liu
mesh_terms: D000595:Amino Acid Sequence; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry*; D008780:Methyltransferases / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary
chemical_list: C489114:CIAPIN1 protein, human; D047908:Intracellular Signaling Peptides and Proteins; D008780:Methyltransferases
keywords: CIAPIN1; anamorsin; crystal structure; methyltransferase-like fold