PDBsum entry 4e9y

Metal binding protein

PDB id: 4e9y

Contents

Protein chains

317 a.a.

Ligands

OXY ×3

Metals

_CL

_CU ×12

Waters ×790

PDB id:

4e9y

Name:

Metal binding protein

Title:

Multicopper oxidase mglac (data4)

Structure:

Multicopper oxidase. Chain: a, b, c. Fragment: unp residues 35-359. Engineered: yes

Source:

Uncultured bacterium. Organism_taxid: 77133. Gene: mco. Expressed in: escherichia coli. Expression_system_taxid: 562

Resolution:

1.50Å R-factor: 0.172

Authors:

H.Komori,K.Miyazaki,Y.Higuchi

Key ref:

H.Komori et al. (2014). New insights into the catalytic active-site structure of multicopper oxidases. Acta Crystallogr D Biol Crystallogr, 70, 772-779. PubMed id: 24598746 DOI: 10.1107/S1399004713033051

Date:

21-Mar-12 Release date: 27-Mar-13

Protein chains

C0STU6  (C0STU6_9BACT) -  Multicopper oxidase from uncultured bacterium

Seq: 359 a.a.

Struc: 317 a.a.

DOI no: 10.1107/S1399004713033051

Acta Crystallogr D Biol Crystallogr 70:772-779 (2014)

PubMed id: 24598746

New insights into the catalytic active-site structure of multicopper oxidases.

H.Komori, R.Sugiyama, K.Kataoka, K.Miyazaki, Y.Higuchi, T.Sakurai.

ABSTRACT

Structural models determined by X-ray crystallography play a central role in understanding the catalytic mechanism of enzymes. However, X-ray radiation generates hydrated electrons that can cause significant damage to the active sites of metalloenzymes. In the present study, crystal structures of the multicopper oxidases (MCOs) CueO from Escherichia coli and laccase from a metagenome were determined. Diffraction data were obtained from a single crystal under low to high X-ray dose conditions. At low levels of X-ray exposure, unambiguous electron density for an O atom was observed inside the trinuclear copper centre (TNC) in both MCOs. The gradual reduction of copper by hydrated electrons monitored by measurement of the Cu K-edge X-ray absorption spectra led to the disappearance of the electron density for the O atom. In addition, the size of the copper triangle was enlarged by a two-step shift in the location of the type III coppers owing to reduction. Further, binding of O2 to the TNC after its full reduction was observed in the case of the laccase. Based on these novel structural findings, the diverse resting structures of the MCOs and their four-electron O2-reduction process are discussed.