1MLV: Structure and Catalytic Mechanism of a SET Domain Protein Methyltransferase

Protein lysine methylation by SET domain enzymes regulates chromatin structure, gene silencing, transcriptional activation, plant metabolism, and other processes. The 2.6 A resolution structure of Rubisco large subunit methyltransferase in a pseudo-bisubstrate complex with S-adenosylhomocysteine and a HEPES ion reveals an all-beta architecture for the SET domain embedded within a larger alpha-helical enzyme fold. Conserved regions of the SET domain bind S-adenosylmethionine and substrate lysine at two sites connected by a pore. We propose that methyl transfer is catalyzed by a conserved Tyr at a narrow pore connecting the sites. The cofactor enters by a "back door" on the opposite side of the enzyme from substrate, promoting highly specific protein recognition and allowing addition of multiple methyl groups.
PDB ID: 1MLVDownload
MMDB ID: 20995
PDB Deposition Date: 2002/8/30
Updated in MMDB: 2017/11
Experimental Method:
x-ray diffraction
Resolution: 2.6  Å
Source Organism:
Similar Structures:
Biological Unit for 1MLV: monomeric; determined by author
Molecular Components in 1MLV
Label Count Molecule
Protein (1 molecule)
Ribulose-1,5 Biphosphate Carboxylase/oxygenase Large Subunit N-methyltransferase
Molecule annotation
Chemicals (2 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB