title: Computational Study of Symmetric Methylation on Histone Arginine Catalyzed by Protein Arginine Methyltransferase PRMT5 through QM/MM MD and Free Energy Simulations.
abstract: Protein arginine methyltransferases (PRMTs) catalyze the transfer of the methyl group from S-adenosyl-l-methionine (AdoMet) to arginine residues. There are three types of PRMTs (I, II and III) that produce different methylation products, including asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA) and monomethylarginine (MMA). Since these different methylations can lead to different biological consequences, understanding the origin of product specificity of PRMTs is of considerable interest. In this article, the quantum mechanical/molecular mechanical (QM/MM) molecular dynamics (MD) and free energy simulations are performed to study SDMA catalyzed by the Type II PRMT5 on the basis of experimental observation that the dimethylated product is generated through a distributive fashion. The simulations have identified some important interactions and proton transfers during the catalysis. Similar to the cases involving Type I PRMTs, a conserved Glu residue (Glu435) in PRMT5 is suggested to function as general base catalyst based on the result of the simulations. Moreover, our results show that PRMT5 has an energetic preference for the first methylation on Nη1 followed by the second methylation on a different ω-guanidino nitrogen of arginine (Nη2).The first and second methyl transfers are estimated to have free energy barriers of 19-20 and 18-19 kcal/mol respectively. The computer simulations suggest a distinctive catalytic mechanism of symmetric dimethylation that seems to be different from asymmetric dimethylation.
authors.affiliation: Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA. yyue@vols.utk.edu.
authors.forename: Yufei
authors.initials: Y
authors.lastname: Yue
authors.affiliation: School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116024, China. yzchu@dlut.edu.cn.
authors.forename: Yuzhuo
authors.initials: Y
authors.lastname: Chu
authors.affiliation: Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA. hguo1@utk.edu.|UT/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA. hguo1@utk.edu.
authors.forename: Hong
authors.initials: H
authors.lastname: Guo
mesh_terms: D001120:Arginine / Q000031:analogs & derivatives* / Q000737:chemistry*; D055162:Biocatalysis; D006657:Histones / Q000737:chemistry*; D006801:Humans; D007700:Kinetics; D008745:Methylation; D056004:Molecular Dynamics Simulation; D011484:Protein-Arginine N-Methyltransferases / Q000737:chemistry*; D011522:Protons; D011789:Quantum Theory; D012436:S-Adenosylmethionine / Q000737:chemistry*; D013379:Substrate Specificity; D013816:Thermodynamics
chemical_list: D006657:Histones; D011522:Protons; C018524:N,N-dimethylarginine; D012436:S-Adenosylmethionine; D001120:Arginine; C400529:PRMT5 protein, human; D011484:Protein-Arginine N-Methyltransferases
keywords: asymmetric dimethylarginine (ADMA); protein arginine methyltransferase (PRMT); symmetric dimethylarginine (SDMA)