Structure and Function of RbcX, an Assembly Chaperone for Hexadecameric Rubisco

Structural Analysis of the Rubisco-Assembly Chaperone RbcX-II from Chlamydomonas reinhardtii

The most prevalent form of the Rubisco enzyme is a complex of eight catalytic large subunits (RbcL) and eight regulatory small subunits (RbcS). Rubisco biogenesis depends on the assistance by specific molecular chaperones. The assembly chaperone RbcX stabilizes the RbcL subunits after folding by chaperonin and mediates their assembly to the RbcL8 core complex, from which RbcX is displaced by Rb...

Folding and assembly of RuBisCO / Structural and functional characterization of the RuBisCO assembly chaperone RbcX

Chaperones for folding, assembly and maintenance of Rubisco

Ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) is responsible for the fixation of atmospheric CO2 in photosynthesis. Rubisco is not only the most abundant protein in nature but also one with a remarkably high chaperone requirement for folding, assembly and maintenance. The major form of Rubisco (form I) is hexadecameric, consisting of 8 large (RbcL) and 8 small (RbcS) subunits. The f...

RbcX can function as a rubisco chaperonin, but is non-essential in Synechococcus PCC7942.

In most cyanobacteria, the gene rbcX is co-transcribed with the rbcL and rbcS genes that code for the large and small subunits of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). Previous co-expression studies in Escherichia coli of cyanobacterial Rubisco and RbcX have identified a chaperonin-like function for RbcX. The organization of the rbcLXS operon has, to a certain extent, precl...

Heterologous expression and initial characterization of recombinant RbcX protein from Thermosynechococcus elongatus BP-1 and the role of RbcX in RuBisCO assembly.

In the cyanobacterial RuBisCO operon from Thermosynechococcus elongatus the rbcX gene is juxtaposed and cotranscribed with the rbcL and rbcS genes which encode large and small RuBisCO subunits, respectively. It has been suggested that the rbcX position is not random and that the RbcX protein could be a chaperone for RuBisCO. In this study, the RbcX protein from T. elongatus was overexpressed, p...