PDBsum entry 1kv7

Oxidoreductase

PDB id: 1kv7

Contents

Protein chain

463 a.a. *

Ligands

C2O

Metals

_CU ×2

Waters ×507

* Residue conservation analysis

PDB id:

1kv7

Name:

Oxidoreductase

Title:

Crystal structure of cueo, a multi-copper oxidase from e. Coli involved in copper homeostasis

Structure:

Probable blue-copper protein yack. Chain: a. Synonym: cueo. Engineered: yes

Source:

Escherichia coli. Organism_taxid: 562. Expressed in: escherichia coli bl21. Expression_system_taxid: 511693.

Resolution:

1.40Å R-factor: 0.185 R-free: 0.221

Authors:

S.A.Roberts,A.Weichsel,G.Grass,K.Thakali,J.T.Hazzard,G.Tollin, C.Rensing,W.R.Montfort

Key ref:

S.A.Roberts et al. (2002). Crystal structure and electron transfer kinetics of CueO, a multicopper oxidase required for copper homeostasis in Escherichia coli. Proc Natl Acad Sci U S A, 99, 2766-2771. PubMed id: 11867755 DOI: 10.1073/pnas.052710499

Date:

25-Jan-02 Release date: 06-Feb-02

Protein chain

P36649  (CUEO_ECOLI) -  Multicopper oxidase CueO from Escherichia coli (strain K12)

Seq: 516 a.a.

Struc: 463 a.a.

Enzyme reactions

• Enzyme class: E.C.1.16.3.4 - cuproxidase.
• Reaction: 4 Cu⁺ + O2 + 4 H⁺ = 4 Cu²⁺ + 2 H2O

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

Key reference

DOI no: 10.1073/pnas.052710499

Proc Natl Acad Sci U S A 99:2766-2771 (2002)

PubMed id: 11867755

Crystal structure and electron transfer kinetics of CueO, a multicopper oxidase required for copper homeostasis in Escherichia coli.

S.A.Roberts, A.Weichsel, G.Grass, K.Thakali, J.T.Hazzard, G.Tollin, C.Rensing, W.R.Montfort.

ABSTRACT

CueO (YacK), a multicopper oxidase, is part of the copper-regulatory cue operon in Escherichia coli. The crystal structure of CueO has been determined to 1.4-A resolution by using multiple anomalous dispersion phasing and an automated building procedure that yielded a nearly complete model without manual intervention. This is the highest resolution multicopper oxidase structure yet determined and provides a particularly clear view of the four coppers at the catalytic center. The overall structure is similar to those of laccase and ascorbate oxidase, but contains an extra 42-residue insert in domain 3 that includes 14 methionines, nine of which lie in a helix that covers the entrance to the type I (T1, blue) copper site. The trinuclear copper cluster has a conformation not previously seen: the Cu-O-Cu binuclear species is nearly linear (Cu-O-Cu bond angle = 170 degrees) and the third (type II) copper lies only 3.1 A from the bridging oxygen. CueO activity was maximal at pH 6.5 and in the presence of >100 microM Cu(II). Measurements of intermolecular and intramolecular electron transfer with laser flash photolysis in the absence of Cu(II) show that, in addition to the normal reduction of the T1 copper, which occurs with a slow rate (k = 4 x 10(7) M(-1)x (-1)), a second electron transfer process occurs to an unknown site, possibly the trinuclear cluster, with k = 9 x 10(7) M(-1) x (-1), followed by a slow intramolecular electron transfer to T1 copper (k approximately 10 s(-1)). These results suggest the methionine-rich helix blocks access to the T1 site in the absence of excess copper.

Selected figure(s)

Figure 2.
Fig. 2. Representative electron density (2 F[o] F[c] [c]) after automatic model building and one round of refinement, before manual intervention. The model shown is in the region surrounding the trinuclear copper center and was built automatically with ARP/WARP.

Figure 4.
Fig. 4. Stereoview showing the geometry of the T1 and trinuclear copper sites. Shown are the copper atoms (cyan), oxygen atoms (red), HCH residues (499-501), nitrogens (blue), and sulfurs (yellow) from ligating histidines, cysteines, and methionines. T1 Cu is ligated to His-443, His-503, Cys-500, and Met-510. T2 Cu is ligated to His-101, His-446, and a water molecule. Cu2 is ligated to His-103, His-141, His-501, and the bridging oxygen. Cu3 is ligated to His-143, His-448, His-499, and the bridging oxygen.

Figures were selected by an automated process.