ccmK2 Antibody

One of the shell proteins of the carboxysome, a polyhedral inclusion where RuBisCO (ribulose bisphosphate carboxylase, rbcL-rbcS) is sequestered. Assembles into hexamers which make sheets that form the facets of the polyhedral carboxysome. The hexamer central pore probably regulates metabolite flux.; The major shell protein of the carboxysome, a polyhedral inclusion where RuBisCO (ribulose bisphosphate carboxylase, rbcL-rbcS) is sequestered. Hexamers make sheets that form the facets of the polyhedral carboxysome. The shell is 4.5 nm thick, as observed for CcmK hexamers. Required for recruitment of CcmO to the pre-carboxysome. In PCC 7942 there are several CcmK paralogs with presumably functional differences; replacing the central pore residues (34-37) with those of either CcmK4 from this organism (Tyr-Met-Arg-Ala) or from an alpha-type carboxysome forming cyanobacterium (CsoS1 of P.marinus strain MIT 9313, Arg-Glu-Phe-Val) allows the bacterium to make carboxysomes, but the expression level is too low to know if the carboxysome is functional for CO(2) fixation.; Beta-carboxysome assembly initiates when soluble RuBisCO is condensed into a liquid matrix in a pre-carboxysome by the RbcS-like domains of probably both CcmM58 and CcmM35. CcmN interacts with the N-terminus of CcmM58, and then recruits the CcmK2 major shell protein via CcmN's encapsulation peptide. Shell formation requires CcmK proteins and CcmO. CcmL caps the otherwise elongated carboxysome. Once fully encapsulated carboxysomes are formed, they migrate within the cell probably via interactions with the cytoskeleton.