Functional cyanobacterial beta-carboxysomes have an absolute requirement for both long and short forms of the CcmM protein.

Carboxysomes are an essential part of the cyanobacterial CO2-concentrating mechanism, consisting of a protein shell and an interior of Rubisco. The beta-carboxysome shell protein CcmM forms two peptides via a proposed internal ribosomal entry site (IRES) within the ccmM transcript in Synechococcus PCC7942. The abundant short form (35 kD, M35) consists of Rubisco small subunit-like repeats and binds Rubisco.

Identification of a SulP-type bicarbonate transporter in marine cyanobacteria.

Cyanobacteria possess a highly effective CO(2)-concentrating mechanism that elevates CO(2) concentrations around the primary carboxylase, Rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase). This CO(2)-concentrating mechanism incorporates light-dependent, active uptake systems for CO(2) and HCO(-)(3). Through mutant studies in a coastal marine cyanobacterium, Synechococcus sp.