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Lecture 10: Bacterial Adaptation

Lecture 10: Bacterial Adaptation. Reading assignments in Text: Lengeler et al. 1999 Text: pages 469-483 “Rapid” Enzyme control pages 123-126 ATP / NAD(P)H regulation Lecture 9 Text: pages 674-676 Bacterial diversity pages 700-704 Phylogenetic trees pages 704-716 Early life/ evolution

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Lecture 10: Bacterial Adaptation

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  1. Lecture 10: Bacterial Adaptation Reading assignments in Text: Lengeler et al. 1999 Text: pages 469-483 “Rapid” Enzyme control pages 123-126 ATP / NAD(P)H regulation Lecture 9 Text: pages 674-676 Bacterial diversity pages 700-704 Phylogenetic trees pages 704-716 Early life/ evolution pages 723-728 Food in the real world pages 746-750 Biofilms pages 754-761 Cooperation and methanogens pages 763-774 Bugs in water pages 775-778 Bugs in sediments pages 779-784 Bugs in soil pages 784-792 Bugs in extreme environments pages 879-882 Bugs in food products pages 907-908 Bio-treatment

  2. Lecture Overview Metabolism GROWTH Bacterial populations (lab conditions) Bacteria as single cells (“cell cycles”) Differentiation Symbiosis Sporulation Bacterial Diversity Adaptation Mechanisms Change enzyme activities Rapid Slower Make new enzymes

  3. Rapid adaptation responses/ Demand feeding 14-C glycerol E. coli M9 14-C 19 amino acids Amino acids 14-C MP’s Histidine (-) Feed Back inhibition More active “Allosteric” Cell growth Cell proteins M9 14-C glycerol E. coli 14-C 20 amino acids Cold Histidine Cold Histidine Biosyn. Allows “demand feeding” of Biosynthesis

  4. Feedback systems M9 E. coli Trp Phe Tyr 1) Sequential FB (-), most logical 2) isozymes, different FB targets “metabolic imbalance” 3) cumulative FB(-), most common +Trp Rapid growth Slow, stop growth ?

  5. Global ATP and NADPH allosteric controls N2 O2 CMet. Biosynthesis 12 MP’s ATP Adenylate kinase (+/-) (+/-) +(1/2)[ADP] NAD(P)H AMP + ATP 2 ADP [ATP]+[ADP]+[AMP] X X Stops growth, [ATP] stays high E. coli + O2, rapid growth, [ATP] high [ATP] + (1/2)[ADP] ATP (~P) Energy Charge EC = Theoretical EC = 0-1.0 Physiological EC = 0.87-0.95, <0.5

  6. Stable response point make SRxn rates use 0.0 1.0 EC ATP ADP 2.8 18.5 mMoles ATP (MW = 507) ATP(-) (+)AMP (Rxns make ATP) ATP(+) (Rxns use ATP) (-)AMP Rapid and massive use of ATP 10 msec LB M9 Growing 1.0 gram of E. coli

  7. Allosteric maintainance of reduction power [NADH] Low 0.03 - 0.07 Catabolic Reduction Charge, CRC = [NADH] + [NAD+] [NADPH] High 0.3 - 0.7 Anabolic Reduction Charge, ARC = [NADPH] + [NADP+]

  8. Covalent modifications of bacterial proteins Common Rare =O -Ser-OH -Asp-C-O- ATP ATP Kinase-His~Pi Kinase -Ser-O-PO3-- =O -Asp-C-O-PO3-- Common Common =O -Tyr-OH -Glu-C-O- ATP SAM~CH3 PPi -Tyr-O-AMP =O -Glu-C-O-CH3 AT = Adenyl Trans GS = Glutamine Synthase

  9. Glutamine Synthase (GS) protein 12X(GS) High NH3 12X(GS-Try-AMP) High NH3 e Low NH3 260 l 280 l nm High Enzyme activity Low Enzyme activity

  10. Adaptation to high and low ammonium (-) Cumulative FB inhibition NH3 ] High NH3 (GS-AMP) Glu Gln aKeto “met. delegates” ATP NADPH Trp, His, Carbamyl~P CTP, AMP glucosamine-6-P Biosynthesis No FB inhibition Low NH3 aKeto Extra pool Glu 2x Glu aKeto NH3 NADPH NADPH High use (GS) Gln GS = “N-pump” Biosynthesis ATP Low use

  11. Sensing N and switching GS GS-AMP = Adenyl Tranferase GS Enzyme Activity P-UMP (-) GS mRNA synthesis = Receiver Asp~P The players: GS AT UT = Uridyl Transferase P = Kinase His~P NRII NRI

  12. Sensing N and switching GS GS P P-UMP (-) AT GS-AMP GS NRII -AMP ~P NRI More GS protein glnA mRNA DNA GS Low NH3 Sensor ? UT [Gln / aKeto] High activity No FB inhibition

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