Year: 2019
Type: article
Abstract: SETD3 is an actin histidine-N3 methyltransferase, whereas other characterized SET-domain enzymes are protein lysine methyltransferases. We report that in a pre-reactive complex SETD3 binds the N3-protonated form (N3-H) of actin His73, and in a post-reactive product complex, SETD3 generates the methylated histidine in an N1-protonated (N1-H) and N3-methylated form. During the reaction, the imidazole ring of His73 rotates ~105°, which shifts the proton from N3 to N1, thus ensuring that the target atom N3 is deprotonated prior to the methyl transfer. Under the conditions optimized for lysine deprotonation, SETD3 has weak lysine methylation activity on an actin peptide in which the target His73 is substituted by a lysine. The structure of SETD3 with Lys73-containing peptide reveals a bent conformation of Lys73, with its side chain aliphatic carbons tracing along the edge of imidazole ring and the terminal ε-amino group occupying a position nearly identical to the N3 atom of unmethylated histidine.
Source: Nature Communications
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $5,200
Awards: G111615301, Orbitrap Elite High-Resolution Mass Spectrometer for Proteomics and Metabolomics, G1365419315, A Proteomics and Metabolomics Core Facility at the University of Texas MD Anderson Cancer Center, G2014820758, G4276892241, Histone Lysine deMethylation: Structures, Inhibitions and Mechanisms, G4774279693, G6110703196, G6299710089, Function of PHD Domain Proteins in Chromatin Regulation, G7174521430, Recruitment of Established Investigators, G7833977891, G9000034222, G9000249291
OpenAlex ID: W2965096892