PDBsum entry 2qpp

Oxidoreductase

PDB id: 2qpp

Contents

Protein chains

214 a.a. *

Ligands

HEM ×2

Waters ×83

* Residue conservation analysis

PDB id:

2qpp

Name:

Oxidoreductase

Title:

Crystal structure of human heme oxygenase-2 c127a (ho-2) with bound heme

Structure:

Heme oxygenase 2. Chain: a, b. Synonym: ho-2. Engineered: yes. Mutation: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Gene: hmox2, ho2. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

Resolution:

2.61Å R-factor: 0.205 R-free: 0.256

Authors:

C.M.Bianchetti,C.A.Bingman,E.Bitto,G.E.Wesenberg,G.N.Phillips Jr., Center For Eukaryotic Structural Genomics (Cesg)

Key ref:

C.M.Bianchetti et al. (2007). Comparison of apo- and heme-bound crystal structures of a truncated human heme oxygenase-2. J Biol Chem, 282, 37624-37631. PubMed id: 17965015 DOI: 10.1074/jbc.M707396200

Date:

24-Jul-07 Release date: 07-Aug-07

Protein chains

P30519  (HMOX2_HUMAN) -  Heme oxygenase 2 from Homo sapiens

Seq: 316 a.a.

Struc: 214 a.a.*

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

Enzyme reactions

• Enzyme class: E.C.1.14.14.18 - heme oxygenase (biliverdin-producing).
• Reaction: heme b + 3 reduced [NADPH--hemoprotein reductase] + 3 O2 = biliverdin IXalpha + CO + Fe²⁺ + 3 oxidized [NADPH--hemoprotein reductase] + 3 H2O + H⁺

heme b (Bound ligand (Het Group name = HEM) matches with 95.45% similarity) + 3 × reduced [NADPH--hemoprotein reductase] + 3 × O2 = biliverdin IXalpha + CO + Fe(2+) + 3 × oxidized [NADPH--hemoprotein reductase] + 3 × H2O + H(+)

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

DOI no: 10.1074/jbc.M707396200

J Biol Chem 282:37624-37631 (2007)

PubMed id: 17965015

Comparison of apo- and heme-bound crystal structures of a truncated human heme oxygenase-2.

C.M.Bianchetti, L.Yi, S.W.Ragsdale, G.N.Phillips.

ABSTRACT

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.

Selected figure(s)

Figure 1.
FIGURE 1. Schematic of the overall reaction catalyzed by heme oxygenase.

Figure 5.
FIGURE 5. Electron density maps of apo- and heme-bound HO-2. A, stereo view of the F[o] - F[c] map of the heme-bound HO-2 heme pocket contoured at 3 . The heme group is shown with carbon in gray, oxygen in red, and iron in orange. The red spheres represent water molecules. B, stereo view of the 2 F[o] - F[c] of the hydrophobic region in the heme pocket of apoHO-2 shown at 1 . The Triton X-100 is shown with carbon in yellow and oxygen in red.

The above figures are reprinted by permission from the ASBMB: J Biol Chem (2007, 282, 37624-37631) copyright 2007.

Figures were selected by an automated process.