2ABS
Crystal structure of T. gondii adenosine kinase complexed with AMP-PCP
Summary for 2ABS
| Entry DOI | 10.2210/pdb2abs/pdb |
| Related | 1DGM 1LII 1LIJ 1LIK 1LIO 2A9Y 2A9Z 2AA0 2AB8 |
| Descriptor | adenosine kinase, CHLORIDE ION, SODIUM ION, ... (5 entities in total) |
| Functional Keywords | ribokinase fold; alpha/beta; intermediate conformation, signaling protein, transferase |
| Biological source | Toxoplasma gondii |
| Total number of polymer chains | 1 |
| Total formula weight | 41147.76 |
| Authors | Zhang, Y.,el Kouni, M.H.,Ealick, S.E. (deposition date: 2005-07-16, release date: 2006-01-24, Last modification date: 2023-08-23) |
| Primary citation | Zhang, Y.,El Kouni, M.H.,Ealick, S.E. Structure of Toxoplasma gondii adenosine kinase in complex with an ATP analog at 1.1 angstroms resolution. Acta Crystallogr.,Sect.D, 62:140-145, 2006 Cited by PubMed Abstract: The obligate intracellular parasite Toxoplasma gondii is incapable of synthesizing purine nucleotides de novo and relies completely on purines salvaged from the host cells. Adenosine is the preferred precursor and is phosphorylated by adenosine kinase (AK), the most active enzyme in adenosine metabolism in T. gondii. AK thus represents a potential chemotherapeutic target for the treatment of T. gondii infections. The previously solved structures of unliganded AK and AK in complex with adenosine (or 7-iodotubercidin) and an ATP analog revealed a novel catalytic mechanism. A domain closure triggered by a GG switch upon adenosine binding sequesters the adenosine and gamma-phosphate of ATP from the solvent. The formation of the anion hole induced by the ATP binding completes the structural requirements for catalysis. In the current study, the structure of a binary complex of AK and the non-hydrolysable ATP analog AMP-PCP was determined to 1.1 angstroms resolution. The overall structure is similar to the apoenzyme, with an open conformation. AMP-PCP is bound in two relaxed conformations and without anchoring by Arg136. The induced anion hole is the same as that in the ternary complex AK-adenosine-AMP-PCP. This structure provides direct evidence that ATP binding at millimolar concentrations does not require adenosine binding as a prerequisite. PubMed: 16421444DOI: 10.1107/S090744490503430X PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.1 Å) |
Structure validation
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