Antibiotic resistance plasmids Penicillinase discovery ? Increasing Antibiotic Resistance 1940 1950 1960 1970 1980 1990 2000 Primordial Golden Biochemical Target Genomic HTS Pharmacologic Disenchantment The Dark Ages (Semmelweis) (Semmelweis) (again!) FDA Office of New Drugs A brief history of antibiotics(co-evolution of antibiotics and their resistance) Transmissible fluoroquinolone resistance THE LEAN YEARS * ** MRSA: UK*, US** Production: 50kg……………………………………………………………………………>106 tons
Side Effects of Streptomycin Headache Nausea Hearing difficulties, deafness Ringing sensation in the ears Loss of balance Fatigue Difficulty in passing urine Itchy rashes on the skin but it cured TB! Albert Schatz and Selman Waksman Who deserved the Prize?
Fifty years of “Industrial Research” on Antibiotics Environmental Doubling time: months Aeration: low Nutrients: variable Carbohydrate: limited Water: variable Temperature: 0-40 pH: 2-10 Yield: µgrams Production Doubling time: hours Aeration: high *Nutrients: high and constant Carbohydrate: high Water: unlimited Temperature: 25-30 pH: 6-7 Yield: grams *Typical substrates for fermentation Molasses (blackstrap) Fish Meal (herring, anchovy) Citrus pulp Asparagus juice Cottonseed oil Malt extract Beef extract Bovine blood Pork liver Distillers solubles Hydrolysed rabbit fur
SOME NUMBERS (Revised from Kyrpides, 2009)
Inter-Kingdom Signalling The Parvome (Rumbaugh, 2007)
Origins and Evolution of Bioactive Small Molecules • Distribution: universal, ancient • Bioactivities: wide range, concentration-dependence • Receptors: mostly macromolecules (cross-species) • Structures: small number of major classes (with decoration) • Biosynthesis: frequently “assembly line” • Properties and applications: multitudinous
(bio)Chemical Evolution Hadean Period Meteorites and primordial reactions (RNA World) Ribozymes LUCA (Last Universal Common Ancestor) “Specialised” Microbial & Plant Metabolism Primary Secondary (Modern) Tree of Life
The Tree of Life Bacteria Eukaryotes Archaea Mouse Crenarchaeota Amitochondriate -0.1 Gram positives Proteobacteria Plants Euryarchaeota Cyanobacteria Drosophila 0.1 Age of Dinosaurs Cambrian Precambrian 1.0 Origin of Metazoans -1.0 20% [O2] Origin of Eukaryotes 1.5 Increasing [O2] in atmosphere 2.1 -2.0 2.3 ? Origin of oxygenic photosynthesis -3.0 Anoxic (H2, NH3, CO2,) 3.8 Last common ancestor -4.0 Origin of Prokaryotes Chemical evolution/ Prebiotic synthesis of biomolecules Origin of Earth (4.5 Billion years)
MODULAR ASSEMBLY LINES FOR BIOACTIVE COMPOUNDS Polyketide synthase Tetracycline, rapamycin, erythromycin Nonribosomal peptide synthase Daptomycin, polymixin, vancomycin
Carbonaceous meteorites as sources of chemical intermediates Pizzarello & Shock (2010)
Primordial amino acid components of non-ribosomal peptides β-alanine, α-aminobutyric acid,β-aminobutyricacid, γ-amino-butyric acid, α-amino-isobutyric acid, α,γ-diaminobutyric acid, α,β-diaminopropionic acid, α-hydroxy-γ-aminobutyric acid, isoserine, N-methylalanine, 3-methylglutamic acid, isovaline, norvaline, sarcosine etc…
Diketopiperazines: potential catalysts and signals There are at least three mechanisms for the synthesis of DKPs!
Targets (binding sites) of bioactive small molecules and macromolecular evolution • Transcription (rifampicin, streptolydigin) • Replication (novobiocin) • *Translation (tetracycline, streptomycin, chloramphenicol) • Cell wall synthesis (penicillin, vancomycin) • Metabolic pathways (azaserine) Did bioactive small molecule interactions play roles in the evolution of cellular macromolecules such as ribosomes and polymerases?
Antibiotic Binding Sites (Receptors) on Prokaryote Ribosomes 30S 50S This2.5 mD macromolecule is the sensor/receptor for many signals.
A model for the chronological evolution of the ribosome based on accretion from existing structures. (Note: no interactions with small molecules!) Harish and Caetano-Anolles (2012) PLoS ONE 7(3): e32776. doi:10.1371/journal.pone.0032776
KEEP CLEAN Wash your hands! Tantalus Mountains,BC
THE FUTURE! PNAS 2012,in press.
Analysis of interactive bacterial cell networks Watrouset al 2012.