PDBsum entry 1lft

Oxygen storage/transport

PDB id: 1lft

Contents

Protein chains

141 a.a. *

146 a.a. *

Ligands

HEM ×2

* Residue conservation analysis

PDB id:

1lft

Name:

Oxygen storage/transport

Title:

Oxy hemoglobin (90% relative humidity)

Structure:

Hemoglobin alpha chain. Chain: a. Hemoglobin beta chain. Chain: b

Source:

Homo sapiens. Human. Organism_taxid: 9606. Organism_taxid: 9606

Biol. unit:

Tetramer (from PDB file)

Resolution:

2.60Å R-factor: 0.197 R-free: 0.265

Authors:

B.K.Biswal,M.Vijayan

Key ref:

B.K.Biswal and M.Vijayan (2002). Structures of human oxy- and deoxyhaemoglobin at different levels of humidity: variability in the T state. Acta Crystallogr D Biol Crystallogr, 58, 1155-1161. PubMed id: 12077435 DOI: 10.1107/S0907444902007138

Date:

12-Apr-02 Release date: 12-Oct-02

Protein chain

P69905  (HBA_HUMAN) -  Hemoglobin subunit alpha from Homo sapiens

Seq: 142 a.a.

Struc: 141 a.a.

Protein chain

P68871  (HBB_HUMAN) -  Hemoglobin subunit beta from Homo sapiens

Seq: 147 a.a.

Struc: 146 a.a.

Enzyme reactions

• Enzyme class: Chains A, B: E.C.?

DOI no: 10.1107/S0907444902007138

Acta Crystallogr D Biol Crystallogr 58:1155-1161 (2002)

PubMed id: 12077435

Structures of human oxy- and deoxyhaemoglobin at different levels of humidity: variability in the T state.

B.K.Biswal, M.Vijayan.

ABSTRACT

High-salt crystals of human oxy- and deoxyhaemoglobin have been studied at different levels of environmental humidity and solvent content. The structure of the oxy form remains relatively unchanged at all levels. The deoxy form, however, undergoes a water-mediated transformation when the relative humidity around the crystals is reduced below 93%. The space group is maintained during the transformation, but the unit-cell volume nearly doubles, with two tetrameric molecules in the asymmetric unit of the low-humidity form compared with one in the native crystals. Interestingly, the haem geometry in the low-humidity form is closer to that in the oxy form than to that in the native deoxy form. The quaternary structure of one of the tetramers moves slightly towards that in the oxy form, while that in the other is more different from the oxy form than that in the high-salt native deoxy form. Thus, it would appear that, as in the case of the liganded form, the deoxy form of haemoglobin can also access an ensemble of related T states.

Selected figure(s)

Figure 3.
Figure 3 The relationship between the unit cells of the native and the low-humidity form of deoxyhaemoglobin. The primed symbols correspond to the low-humidity form.

Figure 4.
Figure 4 Haem environment of the -subunit of native deoxy (red), molecule 1 of deoxy 90% r.h. (blue) and oxy (green) structures.

The above figures are reprinted by permission from the IUCr: Acta Crystallogr D Biol Crystallogr (2002, 58, 1155-1161) copyright 2002.

Figures were selected by an automated process.