different than those found in the wild type (compare Figure 2-6 and Figure 2-2A) but still appear to have some proteinaceous contents. Localization of Plasmid Encoded Diol Dehydratase in a ApduCDE Mutant

       To examine the order of diol dehydratase insertion into the organelle, strain GHi 10 was constructed by moving plasmid, pXY39, containing the pduCDE genes under control of an IPTG inducible promoter, into strain BE87 (4pduCDE) via transduction. The localization of diol dehydratase was then examined in cells where expression of diol dehydratase was induced immediately after transfer from rich to PD/succinate minimal medium (before polyhedral organelle formation) (Figure 2-7A) and in cells where expression of diol dehydratase was induced in a mid-log succinate/PD minimal media culture (after polyhedral organelle formation) (Figure 2-7B). In both of these cases some diol dehydratase localized to the polyhedral organelles and no labeling was observed in a control strain without plasmid (Figure 2-7C). Also in both instances large polar bodies appearing to be entirely composed of diol dehydratase were observed. The presence of these polar bodies is most likely due to the excessive amounts of diol dehydratase that were expressed. Based on these results it is difficult to determine if diol dehydratase is packaged into the polyhedra before or after formation of the polyhedral shell since diol dehydratase is not required for organelle formation (see above) and nothing is known about the turnover of these organelles, thus leaving the possibility that diol dehydratase is being incorporated into organelles formed during mid-log phase. Genes Downstream of Diol Dehydratase are Required for the Formation of Polyhedral Organelles

       Aberrant polyhedral organelles were observed in strain RT818 containing a polar insertion downstream of thepduG gene (Figure 2-8) (Bobik et al. 1999). This suggests