EC Number |
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2.7.7.79 | 2.3 A crystal structure of human THG1 shares structural homology with canonical 5'-3' DNA polymerases and adenylyl/guanylyl cyclases, two enzyme families known to use a two-metal-ion mechanism for catalysis |
2.7.7.79 | CaThg1 crystal structure analysis |
2.7.7.79 | crystal structure analysis |
2.7.7.79 | HsThg1-dGTP crystal structure analysis |
2.7.7.79 | in complex with ATP and with GTP. The enzyme is a tetramer. Catalysis of the 3'-5' reaction with 5'-monophosphorylated tRNA necessitates first an activation step, generating a 5'-adenylylated intermediate prior to a second nucleotidyl transfer step, in which a nucleotide is transferred to the tRNA 5'-end. Distinct binding sites are observed for the nucleotides involved in these two steps |
2.7.7.79 | in complex with tRNAHis, ATP and GTP. tRNAHis guanylyltransferase catalyzes reverse (3'-5') nucleotide addition. The directionality of nucleotide polymerization is determined by the orientation of approach of the nucleotide substrate. The tRNA substrate enters the enzyme's active site from the opposite direction (180 degrees flip) compared with similar nucleotide substrates of canonical 5'-3' polymerases, and the finger domains are on opposing sides of the core palm domain. in complexes with ATP and GTP, the adenine base of ATP1 is more deeply embedded into the nucleotide-binding pocket than GTP1 and recognized by hydrogen bonds with the main chain of Asp47, and the side chain of Lys44 interacts directly with ATP1. The base of GTP1 forms hydrogen bonds with the main-chain atoms of Glu43 and Asp47 |
2.7.7.79 | purified GTP-bound Thg1, hanging drop vapor diffusion method, mixing of 0.001 ml of 7 mg/ml protein in 20 mM Tris, pH 8.0, 500 mM NaCl, and 5 mM DTT, with 0.001 ml of reservoir solution consisting of 0.1 M 2-(N-morpholino)ethanesulfonic acid, pH 6.0, and 0.9 M ammonium sulfate, equilibration against 0.5 ml of reservoir solution, X-ray diffraction structure determination and analysis at 3.0 A resolution, molecular replacement method, modelling |