1GR7

Crystal structure of the double mutant Cys3Ser/Ser100Pro from Pseudomonas Aeruginosa at 1.8 A resolution

Summary for 1GR7

• Entry DOI: 10.2210/pdb1gr7/pdb
• Related: 1AG0 1AZN 1AZR 1AZU 1BEX 1CC3 1E5Y 1E5Z 1E65 1E67 1ETJ 1EZL 1GR7 1I53 1ILS 1ILU 1JZE 1JZF 1JZG 1JZH 1JZI 1JZJ 1NZR 1VLX 2AZU 2TSA 2TSB 3AZU 4AZU 5AZU
• Descriptor: AZURIN, COPPER (II) ION (3 entities in total)
• Functional Keywords: electron transport
• Biological source: PSEUDOMONAS AERUGINOSA
• Total number of polymer chains: 4
• Total formula weight: 56141.27

Authors

Okvist, M.,Bonander, N.,Sandberg, A.,Karlsson, B.G.,Krengel, U.,Xue, Y.,Sjolin, L. (deposition date: 2001-12-14, release date: 2002-05-16, Last modification date: 2024-11-06)

Primary citation

Okvist, M.,Bonander, N.,Sandberg, A.,Karlsson, B.G.,Krengel, U.,Xue, Y.,Sjolin, L.
Crystal structure of the double azurin mutant Cys3Ser/Ser100Pro from Pseudomonas aeruginosa at 1.8 A resolution: its folding-unfolding energy and unfolding kinetics.
Biochim.Biophys.Acta, 1596:336-345, 2002

PubMed Abstract: Azurin is a cupredoxin, which functions as an electron carrier. Its fold is dominated by a beta-sheet structure. In the present study, azurin serves as a model system to investigate the importance of a conserved disulphide bond for protein stability and folding/unfolding. For this purpose, we have examined two azurin mutants, the single mutant Cys3Ser, which disrupts azurin's conserved disulphide bond, and the double mutant Cys3Ser/Ser100Pro, which contains an additional mutation at a site distant from the conserved disulphide. The crystal structure of the azurin double mutant has been determined to 1.8 A resolution(2), with a crystallographic R-factor of 17.5% (R(free)=20.8%). A comparison with the wild-type structure reveals that structural differences are limited to the sites of the mutations. Also, the rates of folding and unfolding as determined by CD and fluorescence spectroscopy are almost unchanged. The main difference to wild-type azurin is a destabilisation by approximately 20 kJ x mol(-1), constituting half the total folding energy of the wild-type protein. Thus, the disulphide bond constitutes a vital component in giving azurin its stable fold.

PubMed: 12007613
DOI: 10.1016/s0167-4838(02)00215-7

Experimental method

X-RAY DIFFRACTION (1.8 Å)