1WMP: Crystal Structure Of Amine Oxidase Complexed With Cobalt Ion

The topa quinone (TPQ) cofactor of copper amine oxidase is generated by copper-assisted self-processing of the precursor protein. Metal ion specificity for TPQ biogenesis has been reinvestigated with the recombinant phenylethylamine oxidase from Arthrobacter globiformis. Besides Cu2+ ion, some divalent metal ions such as Co2+, Ni2+, and Zn2+ were also bound to the metal site of the apoenzyme so tightly that they were not replaced by excess Cu2+ ions added subsequently. Although these noncupric metal ions could not initiate TPQ formation under the atmospheric conditions, we observed slow spectral changes in the enzyme bound with Co2+ or Ni2+ ion under the dioxygen-saturating conditions. Resonance Raman spectroscopy and titration with phenylhydrazine provided unambiguous evidence for TPQ formation by Co2+ and Ni2+ ions. Steady-state kinetic analysis showed that the enzymes activated by Co2+ and Ni2+ ions were indistinguishable from the corresponding metal-substituted enzymes prepared from the native copper enzyme (Kishishita, S., Okajima, T., Kim, M., Yamaguchi, H., Hirota, S., Suzuki, S., Kuroda, S., Tanizawa, K., and Mure, M. (2003) J. Am. Chem. Soc. 125, 1041-1055). X-ray crystallographic analysis has also revealed structural identity of the active sites of Co- and Ni-activated enzymes with Cu-enzyme. Thus Cu2+ ion is not the sole metal ion assisting TPQ formation. Co2+ and Ni2+ ions are also capable of forming TPQ, though much less efficiently than Cu2+.
PDB ID: 1WMPDownload
MMDB ID: 34130
PDB Deposition Date: 2004/7/13
Updated in MMDB: 2012/11
Experimental Method:
x-ray diffraction
Resolution: 2  Å
Source Organism:
Similar Structures:
Biological Unit for 1WMP: dimeric; determined by author and by software (PISA)
Molecular Components in 1WMP
Label Count Molecule
Proteins (2 molecules)
Phenylethylamine Oxidase
Molecule annotation
Chemicals (2 molecules)
* Click molecule labels to explore molecular sequence information.

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