1E67

Zn-Azurin from Pseudomonas aeruginosa

Summary for 1E67

• Entry DOI: 10.2210/pdb1e67/pdb
• Related: 1AG0 1AZN 1AZR 1AZU 1BEX 1CC3 1E5Y 1E5Z 1E65 1ETJ 1ILS 1ILU 1NZR 1VLX 2AZU 2TSA 2TSB 3AZU 4AZU 5AZU
• Descriptor: AZURIN, ZINC ION, NITRATE ION, ... (4 entities in total)
• Functional Keywords: electron transport, copper binding
• Biological source: PSEUDOMONAS AERUGINOSA
• Cellular location: Periplasm: P00282
• Total number of polymer chains: 4
• Total formula weight: 56170.84

Authors

Nar, H.,Messerschmidt, A. (deposition date: 2000-08-09, release date: 2000-08-16, Last modification date: 2024-11-06)

Primary citation

Nar, H.,Huber, R.,Messerschmidt, A.,Filippou, A.C.,Barth, M.,Jaquinod, M.,Van De Kamp, M.
Characterization and Crystal Structure of Zinc Azurin, a by-Product of Heterologous Expression in Escherichia Coli of Pseudomonas Aeruginosa Copper Azurin
Eur.J.Biochem., 205:1123-, 1992

PubMed Abstract: Azurin*, a by-product of heterologous expression of the gene encoding the blue copper protein azurin from Pseudomonas aeruginosa in Escherichia coli, was characterized by chemical analysis and electrospray ionization mass spectrometry, and its structure determined by X-ray crystallography. It was shown that azurin* is native azurin with its copper atom replaced by zinc in the metal binding site. Zinc is probably incorporated in the apo-protein after its expression and transport into the periplasm. Holo-azurin can be reconstituted from azurin* by prolonged exposure of the protein to high copper ion concentrations or unfolding of the protein and refolding in the presence of copper ions. An X-ray crystallographic analysis of azurin* at 0.21-nm resolution revealed that the overall structure of azurin is not perturbed by the metal exchange. However, the geometry of the co-ordination sphere changes from trigonal bipyramidal in the case of copper azurin to distorted tetrahedral for the zinc protein. The copper ligand Met121 is no longer co-ordinated to zinc which adopts a position close to the carbonyl oxygen atom from residue Gly45. The polypeptide structure surrounding the metal site undergoes moderate reorganization upon zinc binding. The largest displacement observed is for the carbonyl oxygen from residue Gly45, which is involved in copper and zinc binding. It moves by 0.03 nm towards the zinc, thereby reducing its distance to the metal from 0.29 nm in the copper protein to 0.23 nm in the derivative.

PubMed: 1576995
DOI: 10.1111/J.1432-1033.1992.TB16881.X

Experimental method

X-RAY DIFFRACTION (2.14 Å)