3q20
From Proteopedia
Crystal structure of RbcX C103A mutant from Thermosynechococcus elongatus
Structural highlights
FunctionRBCX_THEVB An RbcL-specific chaperone. Required for assembly of the RbcL8 core (PubMed:19081849) (Probable). The central cleft of the RbcX homodimer (RbcX2) binds the C-terminus of a RbcL monomer, stabilizing the C-terminus and probably preventing its reassociation with chaperonin GroEL-ES. At the same time the peripheral region of RbcX2 binds a second RbcL monomer, bridging the RbcL homodimers in the correct orientation. The RbcX2(2)-bound RbcL dimers then assemble into the RbcL8 core (RbcL8-(RbcX2)8). RbcS binding triggers the release of RbcX2 (By similarity).[UniProtKB:Q44212][1] [2] Publication Abstract from PubMedThe crystal structure of TeRbcX, a RuBisCO assembly chaperone from the cyanobacterium Thermosynechococcus elongatus, a thermophilic organism, has been determined at 1.7 A 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 alpha4 helices. This type of conformational transition is presumably connected to RbcL (the large RuBisCO subunit) binding during the chaperone function of the RuBisCO assembly. Structure of the RuBisCO chaperone RbcX from the thermophilic cyanobacterium Thermosynechococcus elongatus.,Tarnawski M, Krzywda S, Bialek W, Jaskolski M, Szczepaniak A Acta Crystallogr Sect F Struct Biol Cryst Commun. 2011 Aug 1;67(Pt, 8):851-7. Epub 2011 Jul 13. PMID:21821880[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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