N Aghajari1, G Feller, C Gerday, R Haser. 1. Institut de Biologie et Chimie des Protéines UPR 412, CNRS 7 Passage du Vercors 69367 Lyon cedex 07 France.
Abstract
BACKGROUND: . Enzymes from psychrophilic (cold-adapted) microorganisms operate at temperatures close to 0 degreesC, where the activity of their mesophilic and thermophilic counterparts is drastically reduced. It has generally been assumed that thermophily is associated with rigid proteins, whereas psychrophilic enzymes have a tendency to be more flexible. RESULTS: . Insights into the cold adaptation of proteins are gained on the basis of a psychrophilic protein's molecular structure. To this end, we have determined the structure of the recombinant form of a psychrophilic alpha-amylase from Alteromonas haloplanctis at 2.4 A resolution. We have compared this with the structure of the wild-type enzyme, recently solved at 2.0 A resolution, and with available structures of their mesophilic counterparts. These comparative studies have enabled us to identify possible determinants of cold adaptation. CONCLUSIONS: . We propose that an increased resilience of the molecular surface and a less rigid protein core, with less interdomain interactions, are determining factors of the conformational flexibility that allows efficient enzyme catalysis in cold environments.
BACKGROUND: . Enzymes from psychrophilic (cold-adapted) microorganisms operate at temperatures close to 0 degreesC, where the activity of their mesophilic and thermophilic counterparts is drastically reduced. It has generally been assumed that thermophily is associated with rigid proteins, whereas psychrophilic enzymes have a tendency to be more flexible. RESULTS: . Insights into the cold adaptation of proteins are gained on the basis of a psychrophilic protein's molecular structure. To this end, we have determined the structure of the recombinant form of a psychrophilic alpha-amylase from Alteromonas haloplanctis at 2.4 A resolution. We have compared this with the structure of the wild-type enzyme, recently solved at 2.0 A resolution, and with available structures of their mesophilic counterparts. These comparative studies have enabled us to identify possible determinants of cold adaptation. CONCLUSIONS: . We propose that an increased resilience of the molecular surface and a less rigid protein core, with less interdomain interactions, are determining factors of the conformational flexibility that allows efficient enzyme catalysis in cold environments.
Authors: Salvino D'Amico; Paule Claverie; Tony Collins; Daphné Georlette; Emmanuelle Gratia; Anne Hoyoux; Marie-Alice Meuwis; Georges Feller; Charles Gerday Journal: Philos Trans R Soc Lond B Biol Sci Date: 2002-07-29 Impact factor: 6.237
Authors: Nor Hafizah Ahmad Kamarudin; Raja Noor Zaliha Raja Abd Rahman; Mohd Shukuri Mohamad Ali; Thean Chor Leow; Mahiran Basri; Abu Bakar Salleh Journal: Protein J Date: 2014-06 Impact factor: 2.371