2RGZ: Ensemble Refinement Of The Protein Crystal Structure Of Human Heme Oxygenase-2 C127a (ho-2) With Bound Heme

Heme oxygenase (HO) catalyzes the first step in the heme degradation pathway. The crystal structures of apo- and heme-bound truncated human HO-2 reveal a primarily alpha-helical architecture similar to that of human HO-1 and other known HOs. Proper orientation of heme in HO-2 is required for the regioselective oxidation of the alpha-mesocarbon. This is accomplished by interactions within the heme binding pocket, which is made up of two helices. The iron coordinating residue, His(45), resides on the proximal helix. The distal helix contains highly conserved glycine residues that allow the helix to flex and interact with the bound heme. Tyr(154), Lys(199), and Arg(203) orient the heme through direct interactions with the heme propionates. The rearrangements of side chains in heme-bound HO-2 compared with apoHO-2 further elucidate HO-2 heme interactions.
PDB ID: 2RGZDownload
MMDB ID: 60313
PDB Deposition Date: 2007/10/5
Updated in MMDB: 2017/11
Experimental Method:
x-ray diffraction
Resolution: 2.61  Å
Source Organism:
Similar Structures:
Biological Unit for 2RGZ: dimeric; determined by author
Molecular Components in 2RGZ
Label Count Molecule
Proteins (2 molecules)
Heme Oxygenase 2(Gene symbol: HMOX2)
Molecule annotation
Chemicals (2 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB