User:Madeleine Wilson/Sandbox 1: Difference between revisions

The C-terminal domain of lysine methyltransferase is very important for the catalytic activity of the enzyme. The structures of the <scene name='81/811091/C_terminal_domain/1'>C-terminal domain (residues 345-366)</scene> serve the role of stabilizing the structures in the <scene name='81/811091/C_terminal_domain/16'>SET7 domain (residues 193-344)</scene> in the correct orientation for a reaction in the active site.<ref name="Xiao" /> Hydrophobic interactions in the C-terminal domain are mainly responsible for stabilizing the access channel for the lysine methylation site on histone H3. Residues 337-349 create a <scene name='81/811086/Beta-hairpin/1'>beta-hairpin</scene> that stabilizes the orientation of two tyrosine residues Tyr 335 and Tyr337 that form the lysine access channel. Furthermore, the hydrophobic packing of alpha-helix 3 against beta-sheet 19, specifically <scene name='81/811091/C_terminal_domain/13'>residues Leu357 and Phe 299</scene>, stabilize the orientation of the <scene name='81/811091/C_terminal_domain/20'>SAM cofactor</scene> so that its methyl donating group is oriented toward the lysine access channel. The orientation of the SAM cofactor is further stabilized with its hydrophobic interactions with C-terminal domain residues <scene name='81/811091/C_terminal_domain/18'>Trp352 and Glu356</scene>. <ref name="Xiao" />