Molecular basis for histidine N1 position-specific methylatior by CARNMT1

• 来源期刊: 细胞研究（英文版）
• 年，卷（期）: 2018,（4）
• 页码范围: 494-496
• 页数: 3页
• 语种: 英文

摘要

Dear Editor, Methylation often serves as a biochemical strategy to add new traits of the modified residue for recognition and regulation. Besides arginine and lysine methylations, histidine can also undergo methylation in proteins or histidyl peptides, such as ribosome protein Rpl3, actin,1,2 and dipeptide carnosine (β-alanyl-L-histidine).3 The methylation can occur on either N1 or N3 position of the histidine imidazole ring, and such a position specificity is catalyzed by different histidine methyltransferases(Fig. la).1 For instance, yeast YIL110W methylates histidine 243 at the N3 position of yeast Rpl3, which promotes 60S ribosome subunit assembly and the fidelity of translational elongation.4,5 The enzyme CARNMT1 (carnosine N-methyltransferase 1, also known as C9orf41), conserved from yeast to human, was identified as an N1 position-specific methyltransferase that catalyzes the conversion of carnosine to anserine (β-alanyl-N-π-methyl-L-histi-dine) (Fig. la).6 The N1-or N3-specific histidine methylation underscores a position-specific layer of regulation, reminiscent of state-specific methylation of lysine or arginine residues in histones.7 However, due to lack of structural information, the molecular basis underlying substrate recognition and position-specific catalysis remains largely unexplored.