LIST OF FIGURES


Figure

1-1. Structure of cobalam ins                                               . . . 4 1-2. B 12-dependent pathways known in enteric bacteria . 8 1-3. T h e p d u op eron                                                  . . . 14 1-4. R egulation  of the pdu/cob   regulon   .  16 1-5. Putative pathway of aerobic PD degradation in S. enterica . 18 2-1. Construction of plasmid pGH13 used in generating thepduCDE deletion in strain
     B E 8 7                                                                  . 3 3 2-2. Electron micrographs of S. enterica grown under different conditions . 36 2-3. Aerobic growth of S. enterica on PD minimal medium . 38 2-4. Complementation of apduA::TPOP insertion mutant . 42 2-5. Complementation of apduB: :TPOP insertion mutant . 43 2-6. Electron micrograph of a ApduCDE mutant grown on succinate minimal medium
     in the presence of P D                                               . . . 4 5 2-7. Packaging of diol dehydratase                                         .  47 2-8. Electron micrograph of the aberrant polyhedra formed by S. entericapdu mutant
     R T 8 18 (pdu-8:.'M udJ)                                             . . . 48 3-1. Overexpression and purification of the His6-PduA protein . 66 3-2. Overexpression of the His6-PduA protein in E. coi strain BE230 . 67 3-3. Western analysis with untreated and absorbed anti-PduA polyclonal antiserum
     p rep aratio n s                                                     . . . 6 9 3-4. Localization of diol dehydratase and the PduA protein by immunoelectron
     m ic ro sc o p y   . 7 1