Carboxysome assembly protein CsoS2B

UniProtKB accession:  O85041

Grouped By:  Matching UniProtKB accession

UniProtKB description:  Required for alpha-carboxysome (Cb) assembly, mediates interaction between RuBisCO and the Cb shell (PubMed:25826651, PubMed:32123388) (Probable). The 3 C-terminal repeats act as the encapsulation signal to target proteins to the Cb; they are necessary and sufficient to target both CsoS2 and foreign proteins to the Cb (PubMed:33116131). The N-terminal repeats of this (probably) intrinsically disordered protein bind simultaneously to both subunits of RuBisCO; minimally 2 N-repeats are necessary for RuBisCO assembly into the Cb in vivo. Probably also interacts with the major shell proteins (CsoS1); that interaction would increase the local concentration of CsoS2 so that it can condense RuBisCO and full carboxysomes can be formed (PubMed:32123388). The long form is essential for Cb formation while the short form is not (PubMed:26608811). There are estimated to be 143 CsoS2A and 186 CsoS2B proteins per Cb (Ref.4).