1A4F

BAR-HEADED GOOSE HEMOGLOBIN (OXY FORM)

Summary for 1A4F

• Entry DOI: 10.2210/pdb1a4f/pdb
• Descriptor: HEMOGLOBIN (ALPHA CHAIN), HEMOGLOBIN (BETA CHAIN), PROTOPORPHYRIN IX CONTAINING FE, ... (5 entities in total)
• Functional Keywords: oxygen transport, heme, respiratory protein, erythrocyte
• Biological source: Anser indicus (bar-headed goose); More
• Total number of polymer chains: 2
• Total formula weight: 32972.52

Authors

Zhang, J.,Gu, X. (deposition date: 1998-01-29, release date: 1998-04-29, Last modification date: 2024-02-07)

Primary citation

Zhang, J.,Hua, Z.,Tame, J.R.,Lu, G.,Zhang, R.,Gu, X.
The crystal structure of a high oxygen affinity species of haemoglobin (bar-headed goose haemoglobin in the oxy form).
J.Mol.Biol., 255:484-493, 1996

PubMed Abstract: We have determined the crystal structure of bar-headed goose haemoglobin in the oxy form to a resolution of 2.0 A. The R-factor of the model is 19.8%. The structure is similar to human HbA, but contacts between the subunits show slightly altered packing of the tetramer. Bar-headed goose blood shows a greatly elevated oxygen affinity compared to closely related species of geese. This is apparently due to a single proline to alanine mutation at the alpha 1 beta 1 interface which destabilises the T state of the protein. The beta chain N and C termini are well-localized, and together with other neighbouring basic groups they form a strongly positively charged groove at the entrance to the central cavity around the molecular dyad. The well-ordered conformation and the three-dimensional distribution of positive charges clearly indicate this area to be the inositol pentaphosphate binding site of bird haemoglobins.

PubMed: 8568892
DOI: 10.1006/jmbi.1996.0040

Experimental method

X-RAY DIFFRACTION (2 Å)