1LJW

Crystal Structure of Human Carbonmonoxy Hemoglobin at 2.16 A: A Snapshot of the Allosteric Transition

Summary for 1LJW

• Entry DOI: 10.2210/pdb1ljw/pdb
• Descriptor: hemoglobin alpha chain, hemoglobin beta chain, CARBON MONOXIDE, ... (6 entities in total)
• Functional Keywords: hemoglobin, r state, allosteric, carbonmonoxy, oxygen storage-transport complex, oxygen storage/transport
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 2
• Total formula weight: 32424.52

Authors

Safo, M.K.,Burnett, J.C.,Musayev, F.N.,Nokuri, S.,Abraham, D.J. (deposition date: 2002-04-22, release date: 2002-05-01, Last modification date: 2023-08-16)

Primary citation

Safo, M.K.,Burnett, J.C.,Musayev, F.N.,Nokuri, S.,Abraham, D.J.
Structure of human carbonmonoxyhemoglobin at 2.16 A: a snapshot of the allosteric transition.
Acta Crystallogr.,Sect.D, 58:2031-2037, 2002

PubMed Abstract: A 2.16 A resolution structure of high-salt human carbonmonoxyhemoglobin crystallized at pH 6.4 is reported. The quaternary structure is similar to that of 'classic' R-state hemoglobin; however, subtle but significant tertiary structural changes are observed at the alpha(1)beta(2) and symmetrically equivalent alpha(2)beta(1) interfaces--these are the key subunit interfaces that govern the allosteric transition between the R and T states. Specifically, the movement and weakening of two important hydrogen bonds that are diagnostic for R-state structures, beta(2)His97-alpha(1)Thr38 and beta(2)Arg40-alpha(1)Thr41, have been observed. In addition, a phosphate molecule bound between the two beta-subunits (at the entrance to the central water cavity) has been identified and electron density indicates that this molecule occupies two alternate positions that are related by the dyad axis. Both positions superimpose on the 2,3-diphosphoglycerate binding site. One phosphate conformer interacts with beta(2)Asn139, beta(1)His143 and beta(1)His146, while the second interacts with symmetry-related counterparts (beta(1)Asn139, beta(2)His143 and beta(2)His146).

PubMed: 12454461
DOI: 10.1107/S0907444902015809

Experimental method

X-RAY DIFFRACTION (2.16 Å)