title: Trading off stability against activity in extremophilic aldolases.
abstract: Understanding enzyme stability and activity in extremophilic organisms is of great biotechnological interest, but many questions are still unsolved. Using 2-deoxy-D-ribose-5-phosphate aldolase (DERA) as model enzyme, we have evaluated structural and functional characteristics of different orthologs from psychrophilic, mesophilic and hyperthermophilic organisms. We present the first crystal structures of psychrophilic DERAs, revealing a dimeric organization resembling their mesophilic but not their thermophilic counterparts. Conversion into monomeric proteins showed that the native dimer interface contributes to stability only in the hyperthermophilic enzymes. Nevertheless, introduction of a disulfide bridge in the interface of a psychrophilic DERA did confer increased thermostability, suggesting a strategy for rational design of more durable enzyme variants. Constraint network analysis revealed particularly sparse interactions between the substrate pocket and its surrounding α-helices in psychrophilic DERAs, which indicates that a more flexible active center underlies their high turnover numbers.
authors.affiliation: Institute of Bioorganic Chemistry, Heinrich-Heine-Universität Düsseldorf im Forschungszentrum Jülich, and Bioeconomy Science Center (BioSC), Jülich, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Dick
authors.affiliation: Institute of Complex Systems ICS-6: Structural Biochemistry, Forschungszentrum Jülich GmbH, Jülich, Germany.
authors.forename: Oliver H
authors.initials: OH
authors.lastname: Weiergräber
authors.affiliation: Institute of Bio- and Geosciences IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Classen
authors.affiliation: Institute of Bioorganic Chemistry, Heinrich-Heine-Universität Düsseldorf im Forschungszentrum Jülich, and Bioeconomy Science Center (BioSC), Jülich, Germany.
authors.forename: Carolin
authors.initials: C
authors.lastname: Bisterfeld
authors.affiliation: Institute of Bioorganic Chemistry, Heinrich-Heine-Universität Düsseldorf im Forschungszentrum Jülich, and Bioeconomy Science Center (BioSC), Jülich, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Bramski
authors.affiliation: Institute of Pharmaceutical and Medicinal Chemistry, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Gohlke
authors.affiliation: Institute of Bioorganic Chemistry, Heinrich-Heine-Universität Düsseldorf im Forschungszentrum Jülich, and Bioeconomy Science Center (BioSC), Jülich, Germany.|Institute of Bio- and Geosciences IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Pietruszka
mesh_terms: D000446:Aldehyde-Lyases / Q000737:chemistry* / Q000378:metabolism; D001105:Archaea / Q000201:enzymology; D001419:Bacteria / Q000201:enzymology; D020134:Catalytic Domain; D004795:Enzyme Stability; D000071825:Extremophiles / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D000072756:Protein Conformation, alpha-Helical; D013329:Structure-Activity Relationship
chemical_list: D000446:Aldehyde-Lyases