1S8C

Crystal structure of human heme oxygenase in a complex with biliverdine

Summary for 1S8C

• Entry DOI: 10.2210/pdb1s8c/pdb
• Descriptor: Heme oxygenase 1, BILIVERDINE IX ALPHA (3 entities in total)
• Functional Keywords: heme oxygenase-1, heme degradation, oxidoreductase
• Biological source: Homo sapiens (human)
• Cellular location: Microsome: P09601
• Total number of polymer chains: 4
• Total formula weight: 108177.11

Authors

Lad, L.,Friedman, J.,Li, H.,Bhaskar, B.,Ortiz de Montellano, P.R.,Poulos, T.L. (deposition date: 2004-02-02, release date: 2004-08-03, Last modification date: 2023-08-23)

Primary citation

Lad, L.,Friedman, J.,Li, H.,Bhaskar, B.,Ortiz De Montellano, P.R.,Poulos, T.L.
Crystal Structure of Human Heme Oxygenase-1 in a Complex with Biliverdin
Biochemistry, 43:3793-3801, 2004

PubMed Abstract: Heme oxygenase oxidatively cleaves heme to biliverdin, leading to the release of iron and CO through a process in which the heme participates both as a cofactor and as a substrate. Here we report the crystal structure of the product, iron-free biliverdin, in a complex with human HO-1 at 2.19 A. Structural comparisons of the human biliverdin-HO-1 structure with its heme complex and the recently published rat HO-1 structure in a complex with the biliverdin-iron chelate [Sugishima, M., Sakamoto, H., Higashimoto, Y., Noguchi, M., and Fukuyama, K. (2003) J. Biol. Chem. 278, 32352-32358] show two major differences. First, in the absence of an Fe-His bond and solvent structure in the active site, the distal and proximal helices relax and adopt an "open" conformation which most likely encourages biliverdin release. Second, iron-free biliverdin occupies a different position and orientation relative to heme and the biliverdin-iron complex. Biliverdin adopts a more linear conformation and moves from the heme site to an internal cavity. These structural results provide insight into the rate-limiting step in HO-1 catalysis, which is product, biliverdin, release.

PubMed: 15049686
DOI: 10.1021/bi035451l

Experimental method

X-RAY DIFFRACTION (2.19 Å)