PDBsum entry 1nqp

Oxygen storage/transport

PDB id: 1nqp

Contents

Protein chains

141 a.a. *

146 a.a. *

Ligands

CYN-HEM ×4

Waters ×671

* Residue conservation analysis

PDB id:

1nqp

Name:

Oxygen storage/transport

Title:

Crystal structure of human hemoglobin e at 1.73 a resolution

Structure:

Hemoglobin alpha chain. Chain: a, c. Hemoglobin beta chain. Chain: b, d

Source:

Homo sapiens. Human. Organism_taxid: 9606. Other_details: purified from e/beta thalassemia blood samples. Organism_taxid: 9606

Biol. unit:

Tetramer (from PQS)

Resolution:

1.73Å R-factor: 0.191 R-free: 0.211

Authors:

J.Dasgupta,U.Sen,D.Choudhury,P.Dutta,S.Basu,A.Chakrabarti, A.Chakrabarty,J.K.Dattagupta

Key ref:

J.Dasgupta et al. (2003). Crystallization and preliminary X-ray structural studies of hemoglobin A2 and hemoglobin E, isolated from the blood samples of beta-thalassemic patients. Biochem Biophys Res Commun, 303, 619-623. PubMed id: 12659864 DOI: 10.1016/S0006-291X(03)00379-6

Date:

22-Jan-03 Release date: 02-Mar-04

Protein chains

P69905  (HBA_HUMAN) -  Hemoglobin subunit alpha from Homo sapiens

Seq: 142 a.a.

Struc: 141 a.a.

Protein chains

P68871  (HBB_HUMAN) -  Hemoglobin subunit beta from Homo sapiens

Seq: 147 a.a.

Struc: 146 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

DOI no: 10.1016/S0006-291X(03)00379-6

Biochem Biophys Res Commun 303:619-623 (2003)

PubMed id: 12659864

Crystallization and preliminary X-ray structural studies of hemoglobin A2 and hemoglobin E, isolated from the blood samples of beta-thalassemic patients.

J.Dasgupta, U.Sen, D.Choudhury, P.Datta, A.Chakrabarti, S.B.Chakrabarty, A.Chakrabarty, J.K.Dattagupta.

ABSTRACT

Hemoglobin A(2) (alpha(2)delta(2)), a minor (2-3%) component of circulating red blood cells, acts as an anti-sickling agent and its elevated concentration in beta-thalassemia is a useful clinical diagnostic. In beta-thalassemia major, where there is a failure of beta-chain production, HbA(2) acts as the predominant oxygen delivery mechanism. Hemoglobin E, is another common abnormal hemoglobin, caused by splice site mutation in exon 1 of beta globin gene, when combines with beta-thalassemia, causes severe microcytic anemia. The purification, crystallization, and preliminary structural studies of HbA(2) and HbE are reported here. HbA(2) and HbE are purified by cation exchange column chromatography in presence of KCN from the blood samples of individuals suffering from beta-thalassemia minor and E beta-thalassemia. X-ray diffraction data of HbA(2) and HbE were collected upto 2.1 and 1.73 A, respectively. HbA(2) crystallized in space group P2(1) with unit cell parameters a=54.33 A, b=83.73 A, c=62.87 A, and beta=99.80 degrees whereas HbE crystallized in space group P2(1)2(1)2(1) with unit cell parameters a=60.89 A, b=95.81 A, and c=99.08 A. Asymmetric unit in each case contains one Hb tetramer in R(2) state.