PDBsum entry 1qhq

Electron transfer

PDB id: 1qhq

Contents

Protein chain

139 a.a. *

Ligands

SO4 ×2

Metals

_CU

_CL

Waters ×247

* Residue conservation analysis

PDB id:

1qhq

Name:

Electron transfer

Title:

Auracyanin, a blue copper protein from the green thermophilic photosynthetic bacterium chloroflexus aurantiacus

Structure:

Protein (auracyanin). Chain: a

Source:

Chloroflexus aurantiacus. Organism_taxid: 1108. Cellular_location: peripheral membrane protein. Other_details: green gliding thermophilic photosynthetic bacterium

Resolution:

1.55Å R-factor: 0.198 R-free: 0.233

Authors:

C.S.Bond,R.E.Blankenship,H.C.Freeman,J.M.Guss,M.Maher,F.Selvaraj, M.C.J.Wilce,K.Willingham

Key ref:

C.S.Bond et al. (2001). Crystal structure of auracyanin, a "blue" copper protein from the green thermophilic photosynthetic bacterium Chloroflexus aurantiacus. J Mol Biol, 306, 47-67. PubMed id: 11178893 DOI: 10.1006/jmbi.2000.4201

Date:

25-May-99 Release date: 07-Mar-01

Protein chain

P27197  (AURB_CHLAA) -  Auracyanin-B from Chloroflexus aurantiacus (strain ATCC 29366 / DSM 635 / J-10-fl)

Seq: 235 a.a.

Struc: 139 a.a.

DOI no: 10.1006/jmbi.2000.4201

J Mol Biol 306:47-67 (2001)

PubMed id: 11178893

Crystal structure of auracyanin, a "blue" copper protein from the green thermophilic photosynthetic bacterium Chloroflexus aurantiacus.

C.S.Bond, R.E.Blankenship, H.C.Freeman, J.M.Guss, M.J.Maher, F.M.Selvaraj, M.C.Wilce, K.M.Willingham.

ABSTRACT

Auracyanin B, one of two similar blue copper proteins produced by the thermophilic green non-sulfur photosynthetic bacterium Chloroflexus aurantiacus, crystallizes in space group P6(4)22 (a=b=115.7 A, c=54.6 A). The structure was solved using multiple wavelength anomalous dispersion data recorded about the CuK absorption edge, and was refined at 1.55 A resolution. The molecular model comprises 139 amino acid residues, one Cu, 247 H(2)O molecules, one Cl(-) and two SO(4)(2-). The final residual and estimated standard uncertainties are R=0.198, ESU=0.076 A for atomic coordinates and ESU=0.05 A for Cu---ligand bond lengths, respectively. The auracyanin B molecule has a standard cupredoxin fold. With the exception of an additional N-terminal strand, the molecule is very similar to that of the bacterial cupredoxin, azurin. As in other cupredoxins, one of the Cu ligands lies on strand 4 of the polypeptide, and the other three lie along a large loop between strands 7 and 8. The Cu site geometry is discussed with reference to the amino acid spacing between the latter three ligands. The crystallographically characterized Cu-binding domain of auracyanin B is probably tethered to the periplasmic side of the cytoplasmic membrane by an N-terminal tail that exhibits significant sequence identity with known tethers in several other membrane-associated electron-transfer proteins.

Selected figure(s)

Figure 1.
Figure 1. The photosynthetic electron-transfer cycle in Chloroflexus aurantiacus (adapted from [Blankenship 1994]).

Figure 4.
Figure 4. Schematic of the topology (polypeptide fold) of CaAc-B, adapted from a similar diagram for azurin [Guss et al 1988]. The numerals identify the strands of the polypeptide backbone. The broken line represents a largeloop at the southern end of the auracyanin molecule, culminating in the additional N-terminal strand (strand 0). The solid circlesrepresent the locations of the four Cu-binding residues.

The above figures are reprinted by permission from Elsevier: J Mol Biol (2001, 306, 47-67) copyright 2001.

Figures were selected by an automated process.