Table 2

Carboxysome morphologies in α- and β-carboxysome mutantsa

Carboxysome morphologyMutant gene [reference(s)]
α-Carboxysomesβ-Carboxysomes
Wild typecsoS4ABb (92)ccmK3 (159)
csoS1A (177)ccmK4 (159)
csoS3 (91)ccmK3-ccmK4 (159)
csoS1Dc (122)ccaA (73, 94, 174, 246)
Elongated (vertex protein deficit)csoS4ABb (92)ccmL (93, 94, 140)
Polar body (shell recruitment deficit)ccmK2 (140, 159)
ccmO (159)
ccmN (143, 150, 151)
rbcSd (153)
Aggregated (carboxysome localization deficit)ccmK3K4 (159)
parA (181)
mreB (181)
NoneccmMe (97, 140142, 151)
ccmO (163)
rbcLSf (176)
Empty shellrbcL (121)
  • a The α-carboxysome mutants were largely generated in H. neapolitanus, and the β-carboxysome mutants in S. elongatus PCC 7942, though Synechocystis PCC 6803 and Synechococcus PCC 7002 mutants are included in this table.

  • b Most carboxysomes in Halothiobacillus csoS4AB::Kanr are ultrastructurally normal, but the proportion that are elongated exceeds that of the wild type (92).

  • c When the H. neapolitanus cso operon was expressed without csoS1D, the resulting α-carboxysomes were slightly aberrant, though essentially wild type (122).

  • d Extended rbcS reading frame mutant (153).

  • e Mutant 28 (151) is probably an insertional mutant of ccmM.

  • f The cyanorubrum mutant replaced the native rbcLS genes with the type II RubisCO rbcM gene, abolishing carboxysomes in Synechocystis PCC 6803 (176).