1gr7
From Proteopedia
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CRYSTAL STRUCTURE OF THE DOUBLE MUTANT CYS3SER/SER100PRO FROM PSEUDOMONAS AERUGINOSA AT 1.8 A RESOLUTION
Overview
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.
About this Structure
1GR7 is a Single protein structure of sequence from Pseudomonas aeruginosa with as ligand. Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
Crystal structure of the double azurin mutant Cys3Ser/Ser100Pro from Pseudomonas aeruginosa at 1.8 A resolution: its folding-unfolding energy and unfolding kinetics., Okvist M, Bonander N, Sandberg A, Karlsson BG, Krengel U, Xue Y, Sjolin L, Biochim Biophys Acta. 2002 Apr 29;1596(2):336-45. PMID:12007613
Page seeded by OCA on Thu Feb 21 12:53:05 2008
