4WD4

Crystal structure of human HO1 H25R


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.95 Å
  • R-Value Free: 0.259 
  • R-Value Work: 0.203 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

In-Cell Enzymology To Probe His-Heme Ligation in Heme Oxygenase Catalysis

Sigala, P.A.Morante, K.Tsumoto, K.Caaveiro, J.M.Goldberg, D.E.

(2016) Biochemistry 55: 4836-4849

  • DOI: 10.1021/acs.biochem.6b00562
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Heme oxygenase (HO) is a ubiquitous enzyme with key roles in inflammation, cell signaling, heme disposal, and iron acquisition. HO catalyzes the oxidative conversion of heme to biliverdin (BV) using a conserved histidine to coordinate the iron atom o ...

    Heme oxygenase (HO) is a ubiquitous enzyme with key roles in inflammation, cell signaling, heme disposal, and iron acquisition. HO catalyzes the oxidative conversion of heme to biliverdin (BV) using a conserved histidine to coordinate the iron atom of bound heme. This His-heme interaction has been regarded as being essential for enzyme activity, because His-to-Ala mutants fail to convert heme to biliverdin in vitro. We probed a panel of proximal His mutants of cyanobacterial, human, and plant HO enzymes using a live-cell activity assay based on heterologous co-expression in Escherichia coli of each HO mutant and a fluorescent biliverdin biosensor. In contrast to in vitro studies with purified proteins, we observed that multiple HO mutants retained significant activity within the intracellular environment of bacteria. X-ray crystallographic structures of human HO1 H25R with bound heme and additional functional studies suggest that HO mutant activity inside these cells does not involve heme ligation by a proximal amino acid. Our study reveals unexpected plasticity in the active site binding interactions with heme that can support HO activity within cells, suggests important contributions by the surrounding active site environment to HO catalysis, and can guide efforts to understand the evolution and divergence of HO function.


    Organizational Affiliation

    Departments of Medicine and Molecular Microbiology, Washington University School of Medicine , St. Louis, Missouri 63110, United States.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Heme oxygenase 1
A, B, C, D
292Homo sapiensMutation(s): 1 
Gene Names: HMOX1 (HO, HO1)
EC: 1.14.14.18
Find proteins for P09601 (Homo sapiens)
Go to Gene View: HMOX1
Go to UniProtKB:  P09601
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
EPE
Query on EPE

Download SDF File 
Download CCD File 
B, D
4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID
HEPES
C8 H18 N2 O4 S
JKMHFZQWWAIEOD-UHFFFAOYSA-N
 Ligand Interaction
HEM
Query on HEM

Download SDF File 
Download CCD File 
A, B, C, D
PROTOPORPHYRIN IX CONTAINING FE
HEME
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.95 Å
  • R-Value Free: 0.259 
  • R-Value Work: 0.203 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 74.080α = 90.00
b = 54.410β = 99.09
c = 122.280γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2015-09-09
    Type: Initial release
  • Version 1.1: 2016-08-24
    Type: Database references
  • Version 1.2: 2016-09-14
    Type: Database references