Open AccessStructure of the RuBisCO chaperone RbcX from the thermophilic cyanobacterium Thermosynechococcus elongatus
Author(s) -
Tarnawski Miroslaw,
Krzywda Szymon,
Bialek Wojciech,
Jaskolski Mariusz,
Szczepaniak Andrzej
Publication year - 2011
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309111018860
Subject(s) - rubisco , thermophile , chaperone (clinical) , biochemistry , chemistry , protein folding , thermostability , protein subunit , mutant , protein structure , photosynthesis , enzyme , medicine , pathology , gene
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.