FIG. 1.

Genotype of the cso operon in the wild type and the Φ(gfp-cbbS)(Hyb)::Kan^r mutant of Halothiobacillus neapolitanus. Shown are the position and approximate length of the large (cbbL) and small (cbbS) subunit genes of RubisCO, the gene encoding putative structural proteins CsoS2A and CsoS2B, the gene for the shell-associated carboxysomal carbonic anhydrase CsoSCA (csoS3), the two paralogs (csoS4A and csoS4B) encoding pentameric vertex proteins, and the three genes (csoS1A, csoS1B, and csoS1C) encoding the shell proteins that form the facets of the icosahedral carboxysome shell. The gfp-cbbS fusion shown for the mutant gives rise to the pH-sensitive GFP-tagged RubisCO packaged inside the mutant carboxysomes. The kanamycin resistance cassette (Kan^r) was included for selection purposes.