Crystal structures of a psychrophilic metalloprotease reveal new insights into catalysis by cold-adapted proteases. - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Proteins - Structure, Function and Bioinformatics Année : 2003

Crystal structures of a psychrophilic metalloprotease reveal new insights into catalysis by cold-adapted proteases.

Résumé

Enzymes from psychrophilic organisms differ from their mesophilic counterparts in having a lower thermostability and a higher specific activity at low and moderate temperatures. It is in general accepted that psychrophilic enzymes are more flexible to allow easy accommodation and transformation of the substrates at low energy costs. Here, we report the structures of two crystal forms of the alkaline protease from an Antarctic Pseudomonas species (PAP), solved to 2.1- and 1.96-A resolution, respectively. Comparative studies of PAP structures with mesophilic counterparts show that the overall structures are similar but that the conformation of the substrate-free active site in PAP resembles that of the substrate-bound region of the mesophilic homolog, with both an active-site tyrosine and a substrate-binding loop displaying a conformation as in the substrate-bound form of the mesophilic proteases. Further, a region in the catalytic domain of PAP undergoes a conformational change with a loop movement as large as 13 A, induced by the binding of an extra calcium ion. Finally, the active site is more accessible due to deletions occurring in surrounding loop regions.Enzymes from psychrophilic organisms differ from their mesophilic counterparts in having a lower thermostability and a higher specific activity at low and moderate temperatures. It is in general accepted that psychrophilic enzymes are more flexible to allow easy accommodation and transformation of the substrates at low energy costs. Here, we report the structures of two crystal forms of the alkaline protease from an Antarctic Pseudomonas species (PAP), solved to 2.1- and 1.96-A resolution, respectively. Comparative studies of PAP structures with mesophilic counterparts show that the overall structures are similar but that the conformation of the substrate-free active site in PAP resembles that of the substrate-bound region of the mesophilic homolog, with both an active-site tyrosine and a substrate-binding loop displaying a conformation as in the substrate-bound form of the mesophilic proteases. Further, a region in the catalytic domain of PAP undergoes a conformational change with a loop movement as large as 13 A, induced by the binding of an extra calcium ion. Finally, the active site is more accessible due to deletions occurring in surrounding loop regions.
Fichier non déposé

Dates et versions

hal-00313543 , version 1 (27-08-2008)

Identifiants

  • HAL Id : hal-00313543 , version 1

Citer

N. Aghajari, F. Vanpetegem, V. Villeret, Jp Chessa, C. Gerday, et al.. Crystal structures of a psychrophilic metalloprotease reveal new insights into catalysis by cold-adapted proteases.. Proteins - Structure, Function and Bioinformatics, 2003, 50, pp.636-647. ⟨hal-00313543⟩
19 Consultations
0 Téléchargements

Partager

Gmail Facebook X LinkedIn More