1HMO

THE STRUCTURE OF DEOXY AND OXY HEMERYTHRIN AT 2.0 ANGSTROMS RESOLUTION

Summary for 1HMO

• Entry DOI: 10.2210/pdb1hmo/pdb
• Descriptor: HEMERYTHRIN, ACETYL GROUP, MU-OXO-DIIRON, ... (5 entities in total)
• Functional Keywords: oxygen transport
• Biological source: Themiste dyscritum
• Total number of polymer chains: 4
• Total formula weight: 54290.95

Authors

Holmes, M.A.,Letrong, I.,Turley, S.,Sieker, L.C.,Stenkamp, R.E. (deposition date: 1990-10-18, release date: 1992-01-15, Last modification date: 2024-06-05)

Primary citation

Holmes, M.A.,Le Trong, I.,Turley, S.,Sieker, L.C.,Stenkamp, R.E.
Structures of deoxy and oxy hemerythrin at 2.0 A resolution.
J.Mol.Biol., 218:583-593, 1991

PubMed Abstract: The crystallographic structure analyses of deoxy and oxy hemerythrin have been carried out at 2.0 A resolution to extend the low resolution views of the physiological forms of this oxygen-binding protein. Restrained least-squares refinement has produced molecular models giving R-values of 16.8% for deoxy (41,064 reflections from 10 A to 2.0 A) and 17.3% for oxy hemerythrin (40,413 reflections from 10.0 A to 2.0 A). The protein structure in each derivative is very similar to that of myohemerythrin and the various met forms of hemerythrin. The binuclear complex in each derivative retains an oxygen atom bridging the two iron atoms, but the bond lengths found in deoxy hemerythrin support the idea that, in that form, the bridge is protonated, i.e. the bridging group is a hydroxyl. Dioxygen binds to the pentaco-ordinate iron atom in deoxy hemerythrin in the conversion to oxy hemerythrin. The interatomic distances are consistent with the proposed mechanism where the proton from the bridging group is transferred to the bound dioxygen, stabilizing it in the peroxo oxidation state by forming a hydrogen bond between the peroxy group and the bridging oxygen atom.

PubMed: 2016748
DOI: 10.1016/0022-2836(91)90703-9

Experimental method

X-RAY DIFFRACTION (2 Å)