1OM8

CRYSTAL STRUCTURE OF A COLD ADAPTED ALKALINE PROTEASE FROM PSEUDOMONAS TAC II 18, CO-CRYSTALLYZED WITH 10 mM EDTA

Summary for 1OM8

• Entry DOI: 10.2210/pdb1om8/pdb
• Related: 1G9K 1H71 1KAP 1O0Q 1O0T 1OM6 1OM7 1OMJ 1SMP
• Descriptor: SERRALYSIN, CALCIUM ION, SULFATE ION, ... (4 entities in total)
• Functional Keywords: beta jelly roll, hydrolase
• Biological source: Pseudomonas sp. 'TAC II 18'
• Total number of polymer chains: 1
• Total formula weight: 49064.14

Authors

Ravaud, S.,Gouet, P.,Haser, R.,Aghajari, N. (deposition date: 2003-02-25, release date: 2003-07-15, Last modification date: 2024-02-14)

Primary citation

Ravaud, S.,Gouet, P.,Haser, R.,Aghajari, N.
Probing the role of divalent metal ions in a bacterial psychrophilic metalloprotease: binding studies of an enzyme in the crystalline state by x-ray crystallography.
J.Bacteriol., 185:4195-4203, 2003

PubMed Abstract: The psychrophilic alkaline metalloprotease (PAP) produced by a Pseudomonas bacterium isolated in Antarctica belongs to the clan of metzincins, for which a zinc ion is essential for catalytic activity. Binding studies in the crystalline state have been performed by X-ray crystallography in order to improve the understanding of the role of the zinc and calcium ions bound to this protease. Cocrystallization and soaking experiments with EDTA in a concentration range from 1 to 85 mM have resulted in five three-dimensional structures with a distinct number of metal ions occupying the ion-binding sites. Evolution of the structural changes observed in the vicinity of each cation-binding site has been studied as a function of the concentration of EDTA, as well as of time, in the presence of the chelator. Among others, we have found that the catalytic zinc ion was the first ion to be chelated, ahead of a weakly bound calcium ion (Ca 700) exclusive to the psychrophilic enzyme. Upon removal of the catalytic zinc ion, the side chains of the active-site residues His-173, His-179 and Tyr-209 shifted approximately 4, 1.0, and 1.6 A, respectively. Our studies confirm and also explain the sensitivity of PAP toward moderate EDTA concentrations and propose distinct roles for the calcium ions. A new crystal form of native PAP validates our previous predictions regarding the adaptation of this enzyme to cold environments as well as the proteolytic domain calcium ion being exclusive for PAP independent of crystallization conditions.

PubMed: 12837794
DOI: 10.1128/JB.185.14.4195-4203.2003

Experimental method

X-RAY DIFFRACTION (2 Å)