title: Structure of the RuBisCO chaperone RbcX from the thermophilic cyanobacterium Thermosynechococcus elongatus.
abstract: The crystal structure of TeRbcX, a RuBisCO assembly chaperone from the cyanobacterium Thermosynechococcus elongatus, a thermophilic organism, has been determined at 1.7 Å resolution. TeRbcX has an unusual cysteine residue at position 103 that is not found in RbcX proteins from mesophilic organisms. Unlike wild-type TeRbcX, a mutant protein with Cys103 replaced by Ala (TeRbcX-C103A) could be readily crystallized. The structure revealed that the overall fold of the TeRbcX homodimer is similar to those of previously crystallized RbcX proteins. Normal-mode analysis suggested that TeRbcX might adopt an open or closed conformation through a hinge movement pivoted on a kink in two long α4 helices. This type of conformational transition is presumably connected to RbcL (the large RuBisCO subunit) binding during the chaperone function of the RuBisCO assembly.
authors.affiliation: Department of Biophysics, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland.
authors.forename: Miroslaw
authors.initials: M
authors.lastname: Tarnawski
authors.forename: Szymon
authors.initials: S
authors.lastname: Krzywda
authors.forename: Wojciech
authors.initials: W
authors.lastname: Bialek
authors.forename: Mariusz
authors.initials: M
authors.lastname: Jaskolski
authors.forename: Andrzej
authors.initials: A
authors.lastname: Szczepaniak
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D000458:Cyanobacteria / Q000737:chemistry* / Q000378:metabolism; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D008958:Models, Molecular; D018832:Molecular Chaperones / Q000737:chemistry* / Q000378:metabolism; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D012273:Ribulose-Bisphosphate Carboxylase / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D018832:Molecular Chaperones; C522129:RbcX protein, cyanobacteria; D012273:Ribulose-Bisphosphate Carboxylase