1NV6
Fructose-1,6-Bisphosphatase Complex With Magnesium, Fructose-6-Phosphate, Phosphate, EDTA and Thallium (20 mM)
Summary for 1NV6
| Entry DOI | 10.2210/pdb1nv6/pdb |
| Related | 1NUZ 1NV0 1NV1 1NV2 1NV3 1NV4 1NV5 1NV7 |
| Descriptor | Fructose-1,6-Bisphosphatase, 6-O-phosphono-beta-D-fructofuranose, MAGNESIUM ION, ... (7 entities in total) |
| Functional Keywords | bisphosphatase, allosteric enzymes, gluconeogenesis, hydrolase |
| Biological source | Sus scrofa (pig) |
| Total number of polymer chains | 1 |
| Total formula weight | 38212.82 |
| Authors | Choe, J.,Iancu, C.V.,Fromm, H.J.,Honzatko, R.B. (deposition date: 2003-02-02, release date: 2003-07-08, Last modification date: 2023-10-25) |
| Primary citation | Choe, J.Y.,Nelson, S.W.,Fromm, H.J.,Honzatko, R.B. Interaction of Tl+ with product complexes of fructose-1,6-bisphosphatase J.BIOL.CHEM., 278:16008-16014, 2003 Cited by PubMed Abstract: Fructose-1,6-bisphosphatase requires divalent cations (Mg2+, Mn2+, or Zn2+) for catalysis, but a diverse set of monovalent cations (K+, Tl+, Rb+, or NH(4)(+)) will further enhance enzyme activity. Here, the interaction of Tl+ with fructose-1,6-bisphosphatase is explored under conditions that support catalysis. On the basis of initial velocity kinetics, Tl+ enhances catalysis by 20% with a K(a) of 1.3 mm and a Hill coefficient near unity. Crystal structures of enzyme complexes with Mg2+, Tl+, and reaction products, in which the concentration of Tl+ is 1 mm or less, reveal Mg2+ at metal sites 1, 2, and 3 of the active site, but little or no bound Tl+. Intermediate concentrations of Tl+ (5-20 mm) displace Mg2+ from site 3 and the 1-OH group of fructose 6-phosphate from in-line geometry with respect to bound orthophosphate. Loop 52-72 appears in a new conformational state, differing from its engaged conformation by disorder in residues 61-69. Tl+ does not bind to metal sites 1 or 2 in the presence of Mg2+, but does bind to four other sites with partial occupancy. Two of four Tl+ sites probably represent alternative binding sites for the site 3 catalytic Mg2+, whereas the other sites could play roles in monovalent cation activation. PubMed: 12595529DOI: 10.1074/jbc.M212394200 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.15 Å) |
Structure validation
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