Expression of cloned Nitrosospira sp. isolate 40KI RubisCO in R. eutropha analyzed by SDS-PAGE. Protein samples were electrophoresed in an 11 to 18% polyacrylamide gradient denaturing gel. Lanes 1 and 10 contained purified R. eutropha ATCC 17707 chromosomally encoded RubisCO. The positions of the large (L) and small (S) subunits are indicated. Lanes 2 to 9 contained total cellular protein, as follows: lanes 2 to 4, induced cells [lane 2, AE951(pRK310P) (negative control); lane 3, AE951(pAEX3-40KI); lane 4, AE951(pRub20-2)]; lanes 5 to 7, autotrophic cells [lane 5, AE951(pAEX3-40KI); lane 6, AE951(pRub20-2); lane 7, R. eutropha wild-type strain ATCC 17697]; lanes 8 and 9, heterotrophic cells [lane 8, AE951(pAEX3-40KI); lane 9, AE951(pRub20-2)]. The cell preparations were the same as those used to obtain the data shown in Table 1.