3rib | pdb_00003rib
Human lysine methyltransferase Smyd2 in complex with AdoHcy
Structural highlights
Function[SMYD2_HUMAN] Protein-lysine N-methyltransferase that methylates both histones and non-histone proteins. Specifically methylates histone H3 'Lys-4' (H3K4me) and dimethylates histone H3 'Lys-36' (H3K36me2). Has also methyltransferase activity toward non-histone proteins such as p53/TP53 and RB1. Monomethylates 'Lys-370' of p53/TP53, leading to decreased DNA-binding activity and subsequent transcriptional regulation activity of p53/TP53. Monomethylates 'Lys-860' of RB1/RB.[1] [2] [3] [4] Publication Abstract from PubMedThe SET- and myeloid-Nervy-DEAF-1 (MYND)-domain containing (Smyd) lysine methyltransferases 1-3 share relatively high sequence similarity but exhibit divergence in the substrate specificity. Here we report the crystal structure of the full-length human Smyd2 in complex with S-adenosyl-L-homocysteine (AdoHcy). Although the Smyd1-3 enzymes are similar in the overall structure, detailed comparisons demonstrate that they differ substantially in the potential substrate-binding site. The binding site of Smyd3 consists mainly of a deep and narrow pocket, while those of Smyd1 and Smyd2 consist of a comparable pocket and a long groove. In addition, Smyd2, which has lysine methyltransferase activity on histone H3-lysine 36, exhibits substantial differences in the wall of the substrate-binding pocket compared with those of Smyd1 and Smyd3 which have activity specifically on histone H3-lysine 4. The differences in the substrate-binding site might account for the observed divergence in the specificity and methylation state of the substrates. Further modeling study of Smyd2 in complex with a p53 peptide indicates that mono-methylation of p53-Lys(372) might result in steric conflict of the methyl group with the surrounding residues of Smyd2, providing a structural explanation for the inhibitory effect of the SET7/9-mediated mono-methylation of p53-Lys(372) on the Smyd2-mediated methylation of p53-Lys(370). Structure of human lysine methyltransferase Smyd2 reveals insights into the substrate divergence in Smyd proteins.,Xu S, Zhong C, Zhang T, Ding J J Mol Cell Biol. 2011 Jul 1. PMID:21724641[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
| ||||||||||||||||||||
