PDBsum entry 2htn

Metal binding protein, oxidoreductase

PDB id: 2htn

Contents

Protein chains

(+ 2 more) 158 a.a. *

Ligands

HEM ×4

Metals

_FE ×16

Waters ×98

* Residue conservation analysis

PDB id:

2htn

Name:

Metal binding protein, oxidoreductase

Title:

E. Coli bacterioferritin in its as-isolated form

Structure:

Bacterioferritin. Chain: a, b, c, d, e, f, g, h. Synonym: bfr, cytochrome b-1, cytochrome b-557. Ec: 1.16.3.1

Source:

Escherichia coli. Organism_taxid: 511693. Strain: bl21

Biol. unit:

24mer (from PDB file)

Resolution:

2.50Å R-factor: 0.172 R-free: 0.188

Authors:

A.Van Eerde,S.Wolterink-Van Loo,J.Van Der Oost,B.W.Dijkstra

Key ref:

A.van Eerde et al. (2006). Fortuitous structure determination of 'as-isolated' Escherichia coli bacterioferritin in a novel crystal form. Acta Crystallograph Sect F Struct Biol Cryst Commun, 62, 1061-1066. PubMed id: 17077480 DOI: 10.1107/S1744309106039583

Date:

26-Jul-06 Release date: 21-Nov-06

Protein chains

P0ABD3  (BFR_ECOLI) -  Bacterioferritin from Escherichia coli (strain K12)

Seq: 158 a.a.

Struc: 158 a.a.

Enzyme reactions

• Enzyme class: E.C.1.16.3.1 - ferroxidase.
• Reaction: 4 Fe²⁺ + O2 + 4 H⁺ = 4 Fe³⁺ + 2 H2O
• Cofactor: Cu cation

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

Key reference

DOI no: 10.1107/S1744309106039583

Acta Crystallograph Sect F Struct Biol Cryst Commun 62:1061-1066 (2006)

PubMed id: 17077480

Fortuitous structure determination of 'as-isolated' Escherichia coli bacterioferritin in a novel crystal form.

A.van Eerde, S.Wolterink-van Loo, J.van der Oost, B.W.Dijkstra.

ABSTRACT

Escherichia coli bacterioferritin was serendipitously crystallized in a novel cubic crystal form and its structure could be determined to 2.5 A resolution despite a high degree of merohedral twinning. This is the first report of crystallographic data on 'as-isolated' E. coli bacterioferritin. The ferroxidase active site contains positive difference density consistent with two metal ions that had co-purified with the protein. X-ray fluorescence studies suggest that the metal composition is different from that of previous structures and is a mix of zinc and native iron ions. The ferroxidase-centre configuration displays a similar flexibility as previously noted for other bacterioferritins.

Selected figure(s)

Figure 3.
Figure 3 The ferroxidase centre. (a) Stereo figures of [A]-weighted F[o] - F[c] density in the ferroxidase site contoured at 5 , (b) superposition of the ferroxidase centre of the P2[1]3 structure (grey/orange) and the Mn-bound structure (yellow/purple; PDB code 1bcf ; Frolow et al., 1994[Frolow, F., Kalb, A. J. & Yariv, J. (1994). Nature Struct. Biol. 1, 453-460.]) of E. coli bacterioferritin and (c) superposition of the FE2 site environment in the P2[1]3 E. coli bacterioferritin structure (grey) with the corresponding region in the structure of reduced A. vinelandii bacterioferritin (pale green; PDB code 1fkz ; Swartz et al., 2006[Swartz, L., Kuchinskas, M., Li, H., Poulos, T. L. & Lanzilotta, W. N. (2006). Biochemistry, 45, 4421-4428.]). The location of the inner cavity (IC) is indicated. This view is rotated 90° with respect to the previous views.

Figure 4.
Figure 4 X-ray fluorescence scans around the K edges of Mn, Fe, Cu and Zn, as indicated. Plots are corrected for beam intensity and fluorescence is on an arbitrary scale.

The above figures are reprinted from an Open Access publication published by the IUCr: Acta Crystallograph Sect F Struct Biol Cryst Commun (2006, 62, 1061-1066) copyright 2006.

Figures were selected by the author.