1IWE
IMP Complex of the Recombinant Mouse-Muscle Adenylosuccinate Synthetase
Summary for 1IWE
| Entry DOI | 10.2210/pdb1iwe/pdb |
| Related | 1J4B 1LNY 1LON 1LOO |
| Descriptor | Adenylosuccinate Synthetase, ACETATE ION, INOSINIC ACID, ... (5 entities in total) |
| Functional Keywords | purine biosynthesis, ligase, gtp-binding |
| Biological source | Mus musculus (house mouse) |
| Cellular location | Cytoplasm: P28650 |
| Total number of polymer chains | 2 |
| Total formula weight | 101829.61 |
| Authors | Iancu, C.V.,Borza, T.,Fromm, H.J.,Honzatko, R.B. (deposition date: 2002-05-04, release date: 2002-08-28, Last modification date: 2023-10-25) |
| Primary citation | Iancu, C.V.,Borza, T.,Fromm, H.J.,Honzatko, R.B. IMP, GTP, and 6-phosphoryl-IMP complexes of recombinant mouse muscle adenylosuccinate synthetase. J.Biol.Chem., 277:26779-26787, 2002 Cited by PubMed Abstract: Prokaryotes have a single form of adenylosuccinate synthetase that controls the committed step of AMP biosynthesis, but vertebrates have two isozymes of the synthetase. The basic isozyme, which predominates in muscle, participates in the purine nucleotide cycle, has an active site conformation different from that of the Escherichia coli enzyme, and exhibits significant differences in ligand recognition. Crystalline complexes presented here of the recombinant basic isozyme from mouse show the following. GTP alone binds to the active site without inducing a conformational change. IMP in combination with an acetate anion induces major conformational changes and organizes the active site for catalysis. IMP, in the absence of GTP, binds to the GTP pocket of the synthetase. The combination of GTP and IMP results in the formation of a stable complex of 6-phosphoryl-IMP and GDP in the presence or absence of hadacidin. The response of the basic isozyme to GTP alone differs from that of synthetases from plants, and yet the conformation of the mouse basic and E. coli synthetases in their complexes with GDP, 6-phosphoryl-IMP, and hadacidin are nearly identical. Hence, reported differences in ligand recognition among synthetases probably arise from conformational variations observed in partially ligated enzymes. PubMed: 12004071DOI: 10.1074/jbc.M203730200 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.1 Å) |
Structure validation
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