2BKM

Crystal structure of the truncated hemoglobin from Geobacillus stearothermophilus

Summary for 2BKM

• Entry DOI: 10.2210/pdb2bkm/pdb
• Descriptor: TRUNCATED HEMOGLOBIN FROM GEOBACILLUS STEAROTHERMOPHILUS, OXYGEN MOLECULE, PROTOPORPHYRIN IX CONTAINING FE, ... (5 entities in total)
• Functional Keywords: hypothetical protein, oxygen transport, transport, oxygen storage
• Biological source: GEOBACILLUS STEAROTHERMOPHILUS
• Total number of polymer chains: 2
• Total formula weight: 30944.66

Authors

Ilari, A.,Kjelgaard, P.,von Wachenfeldt, C.,Boffi, A.,Chiancone, E. (deposition date: 2006-02-08, release date: 2006-11-29, Last modification date: 2023-12-13)

Primary citation

Ilari, A.,Kjelgaard, P.,von Wachenfeldt, C.,Catacchio, B.,Chiancone, E.,Boffi, A.
Crystal Structure and Ligand Binding Properties of the Truncated Hemoglobin from Geobacillus Stearothermophilus
Arch.Biochem.Biophys., 457:85-, 2007

PubMed Abstract: A novel truncated hemoglobin has been identified in the thermophilic bacterium Geobacillus stearothermophilus (Gs-trHb). The protein has been expressed in Escherichia coli, the 3D crystal structure (at 1.5 Angstroms resolution) and the ligand binding properties have been determined. The distal heme pocket displays an array of hydrogen bonding donors to the iron-bound ligands, including Tyr-B10 on one side of the heme pocket and Trp-G8 indole nitrogen on the opposite side. At variance with the highly similar Bacillus subtilis hemoglobin, Gs-trHb is dimeric both in the crystal and in solution and displays several unique structural properties. In the crystal cell, the iron-bound ligand is not homogeneously distributed within each distal site such that oxygen and an acetate anion can be resolved with relative occupancies of 50% each. Accordingly, equilibrium titrations of the oxygenated derivative in solution with acetate anion yield a partially saturated ferric acetate adduct. Moreover, the asymmetric unit contains two subunits and sedimentation velocity ultracentrifugation data confirm that the protein is dimeric.

PubMed: 17126283
DOI: 10.1016/J.ABB.2006.09.033

Experimental method

X-RAY DIFFRACTION (1.5 Å)