Ligand binding at the transthyretin dimer-dimer interface: structure of the transthyretin-T4Ac complex at 2.2 Angstrom resolution.Neumann, P., Cody, V., Wojtczak, A.
(2005) Acta Crystallogr.,Sect.D 61: 1313-1319
- PubMed: 16204882
- DOI: 10.1107/S0907444905022523
- PubMed Abstract:
- Structures of Human Transthyretin Complexed with Thyroxine at 2.0 A Resolution and 3',5'-Dinitro-N-Acetyl-L-Thyronine at 2.2 A Resolution
Wojtczak, A.,Cody, V.,Luft, J.R.,Pangborn, W.
(1996) Acta Crystallogr.,Sect.D 52: 758
- Structural Aspects of Inotropic Bipyridine Binding. Crystal Structure Determination to 1.9 A of the Human Serum Transthyretin-Milrinone Complex
Wojtczak, A.,Luft, J.R.,Cody, V.
(1993) J.Biol.Chem. 268: 6202
- Mechanism of Molecular Recognition. Structural Aspects of 3,3'-Diiodo-L-Thyronine Binding to Human Serum Transthyretin
Wojtczak, A.,Luft, J.,Cody, V.
(1992) J.Biol.Chem. 267: 353
The crystal structure of the complex of human transthyretin (hTTR) with 3,3',5,5'-tetraiodothyroacetic acid (T4Ac) has been determined to 2.2 Angstrom resolution. The complex crystallizes in the orthorhombic space group P2(1)2(1)2, with unit-cell par ...
The crystal structure of the complex of human transthyretin (hTTR) with 3,3',5,5'-tetraiodothyroacetic acid (T4Ac) has been determined to 2.2 Angstrom resolution. The complex crystallizes in the orthorhombic space group P2(1)2(1)2, with unit-cell parameters a = 43.46, b = 85.85, c = 65.44 Angstrom. The structure was refined to R = 17.3% and R(free) = 21.9% for reflections without any sigma-cutoff. T4Ac is bound in both the forward and the reverse mode in the two binding sites of hTTR. In the forward orientation, T4Ac binds in a position similar to that described for thyroxine (T4) in the orthorhombic hTTR-T4 complex. In this orientation, the iodine substituents of the phenolic ring are bound in the P3'/P2 halogen pockets. In the reverse orientation, which is the major binding mode of T4Ac, the ligand is bound deep in the TTR channel, with the carboxylic group bound in the P3' pocket and forming simultaneous polar interactions with the residues constituting the two hormone-binding sites. Such interactions of a thyroxine-analogue ligand bound in the reverse mode have never been observed in TTR complexes previously.
Institute of Chemistry, N. Copernicus University, Gagarina 7, 87-100 Toruń, Poland.