Structure of oxalate-substituted diferric mare lactoferrin at 2.7 A resolution.
Sharma, A.K., Singh, T.P.(1999) Acta Crystallogr D Biol Crystallogr 55: 1792-1798
- PubMed: 10531474
- DOI: https://doi.org/10.1107/s0907444999009439
- Primary Citation of Related Structures:
1B7Z - PubMed Abstract:
Lactoferrin binds two Fe(3+) and two CO(2-)(3) ions with high affinity. It can also bind other metal ions and anions. In order to determine the perturbations in the environments of the binding sites in the N and C lobes and elsewhere in the protein, the crystal structure of oxalate-substituted diferric mare lactoferrin has been determined at 2.7 A resolution. The final model has a crystallographic R factor of 21.3% for all data in the resolution range 17.0-2.7 A. The substitution of an oxalate anion does not perturb the overall structure of the protein, but produces several significant changes at the metal-binding and anion-binding sites. The binding of the oxalate anion is symmetrical in both the N and C lobes, unlike in diferric dioxalate human lactoferrin, where the oxalate anion binds the metal ion symmetrically in the C lobe and asymmetrically in the N lobe.
Organizational Affiliation:
Department of Biophysics, All India Institute of Medical Sciences, New Delhi 110 029, India.