PDBsum entry 1e65

Electron transport

PDB id: 1e65

Contents

Protein chains

128 a.a. *

Waters ×164

* Residue conservation analysis

PDB id:

1e65

Name:

Electron transport

Title:

Azurin from pseudomonas aeruginosa, apo form

Structure:

Azurin. Chain: a, b, c, d. Engineered: yes

Source:

Pseudomonas aeruginosa. Organism_taxid: 287. Expressed in: escherichia coli. Expression_system_taxid: 83333. Expression_system_variant: kmbl1164

Biol. unit:

Monomer (from PDB file)

Resolution:

1.85Å R-factor: 0.193

Authors:

H.Nar,A.Messerschmidt

Key ref:

H.Nar et al. (1992). Crystal structure of Pseudomonas aeruginosa apo-azurin at 1.85 A resolution. Febs Lett, 306, 119-124. PubMed id: 1633865 DOI: 10.1016/0014-5793(92)80981-L

Date:

08-Aug-00 Release date: 16-Aug-00

Protein chains

P00282  (AZUR_PSEAE) -  Azurin from Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1)

Seq: 148 a.a.

Struc: 128 a.a.

DOI no: 10.1016/0014-5793(92)80981-L

Febs Lett 306:119-124 (1992)

PubMed id: 1633865

Crystal structure of Pseudomonas aeruginosa apo-azurin at 1.85 A resolution.

H.Nar, A.Messerschmidt, R.Huber, M.van de Kamp, G.W.Canters.

ABSTRACT

The 3D structure of apo-azurin from Pseudomonas aeruginosa has been determined at 1.85 A resolution. The crystal structure is composed of two different molecular forms of apo-azurin arranged as hetero-dimers in the tetramer of the asymmetric unit. Form 1 closely resembles the holo-protein lacking copper. Form 2 shows differences in the metal binding site region induced by the incorporation of a solvent molecule into this site. The positions of the copper ligands His46 and His117 are shifted by 0.6 A and 1.6 A. The His117 side chain adopts a position at the surface of the protein, thereby facilitating access to the copper site. The presence of two different molecular forms of apo-azurin in the crystal lattice may reflect an equilibrium between the two forms in solution. 1H-NMR spectra of apo-azurin recorded as a function of pH show that at high pH the line broadening of His35, His46 and His117 resonances is consistent with an interconversion between forms 1 and 2. At low pH, no broadening is observed. This may indicate that here the interconversion is fast on the NMR timescale.

Selected figure(s)

Figure 2.
Fig. 2. Superposition of apo.azurin form 1 (monomer . thick lines) on Cull I) azurin (thin lines). Apart from the absence of the metal and a minor shift of the His 7 side cllaita toward the c~wity, the :ttomic rnodels are indisting.aishable.

Figure 4.
Fig. 4. Superposition ofapo-azuin form 2 (monomer D, thick lines) on Cu(ll) azurin thin lines). Differences between the two structures are entred at l-lis 4~ nd His j iv, The side chain of His = 7 is shlrtcd by 1.6 toward the protein urface without changig the orientation of the imidazole ring. The surface water molecule bou,ad to His = ~7 Ne shifts accordingly. Movement of Met ~ and Phe t~a side chaiqs prvides the space necessary for the His ~7 swinging motion, The His 4~ side chain is moved in the opposite direction (0,6 A). This shift results in a slight positionl adjustment (0.4 A) f the adjacent main chain of residues 8 to 10.

The above figures are reprinted by permission from the Federation of European Biochemical Societies: Febs Lett (1992, 306, 119-124) copyright 1992.

Figures were selected by an automated process.