7U67
Structure of E. coli dGTPase bound to T7 bacteriophage protein Gp1.2 and GTP
Summary for 7U67
| Entry DOI | 10.2210/pdb7u67/pdb |
| Related | 2MDP |
| EMDB information | 26362 |
| Descriptor | Deoxyguanosinetriphosphate triphosphohydrolase, Inhibitor of dGTPase, GUANOSINE-5'-TRIPHOSPHATE, ... (4 entities in total) |
| Functional Keywords | dgtpase, inhibitor, complex, hydrolase |
| Biological source | Escherichia coli str. K-12 substr. MG1655 More |
| Total number of polymer chains | 12 |
| Total formula weight | 423685.30 |
| Authors | Klemm, B.P.,Hsu, A.L.,Borgnia, M.J.,Schaaper, R.M. (deposition date: 2022-03-03, release date: 2022-08-31, Last modification date: 2024-06-12) |
| Primary citation | Klemm, B.P.,Singh, D.,Smith, C.E.,Hsu, A.L.,Dillard, L.B.,Krahn, J.M.,London, R.E.,Mueller, G.A.,Borgnia, M.J.,Schaaper, R.M. Mechanism by which T7 bacteriophage protein Gp1.2 inhibits Escherichia coli dGTPase. Proc.Natl.Acad.Sci.USA, 119:e2123092119-e2123092119, 2022 Cited by PubMed Abstract: Levels of the cellular dNTPs, the direct precursors for DNA synthesis, are important for DNA replication fidelity, cell cycle control, and resistance against viruses. encodes a dGTPase (2'-deoxyguanosine-5'-triphosphate [dGTP] triphosphohydrolase [dGTPase]; gene, Dgt) that establishes the normal dGTP level required for accurate DNA replication but also plays a role in protecting against bacteriophage T7 infection by limiting the dGTP required for viral DNA replication. T7 counteracts Dgt using an inhibitor, the gene product (Gp1.2). This interaction is a useful model system for studying the ongoing evolutionary virus/host "arms race." We determined the structure of Gp1.2 by NMR spectroscopy and solved high-resolution cryo-electron microscopy structures of the Dgt-Gp1.2 complex also including either dGTP substrate or GTP coinhibitor bound in the active site. These structures reveal the mechanism by which Gp1.2 inhibits Dgt and indicate that Gp1.2 preferentially binds the GTP-bound form of Dgt. Biochemical assays reveal that the two inhibitors use different modes of inhibition and bind to Dgt in combination to yield enhanced inhibition. We thus propose an in vivo inhibition model wherein the Dgt-Gp1.2 complex equilibrates with GTP to fully inactivate Dgt, limiting dGTP hydrolysis and preserving the dGTP pool for viral DNA replication. PubMed: 36067314DOI: 10.1073/pnas.2123092119 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (2.5 Å) |
Structure validation
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