Life History Traits and Genome Structure Aerobiosis and G+C Content in Bacteria J.R. Lobry...
-
Upload
kevin-miles -
Category
Documents
-
view
219 -
download
0
Transcript of Life History Traits and Genome Structure Aerobiosis and G+C Content in Bacteria J.R. Lobry...
Life History Traits and Genome Structure
Aerobiosis and G+C Content in Bacteria
J.R. LobryUniversité Claude Bernard - Lyon I
CNRS UMR 5558 & INRIA Helix
FRANCE
Aerobic versus Anaerobic
• You need the presence of O2 to live, you are aerobic (obligate)
• You need the absence of O2 to live, you are anaerobic (obligate)
• [...snip...]
Only Anaerobic Species
Anaerobic and Aerobic Species
Aerobic >> Anaerobic
• In aerobic conditions (with O2) the oxydation of one molecule of glucose (respiration) yields 38 ATP (metabolic currency unit). Short generation times.
• In anaerobic conditions (without O2) the fermentation of one molecule of glucose yields 2 ATP (metabolic currency unit). Long generation times.
The generation time is a life history trait
Life History Traits and Genome Structure
Aerobiosis and G+C Content in Bacteria
J.R. LobryUniversité Claude Bernard - Lyon I
CNRS UMR 5558 & INRIA Helix
FRANCE
Bacteria in the Universal Tree of Life
PseudomonasEscherichia
Halobacterium
Methanobacterium
Desulfurococcus
Halococcus
Methanococcus
Thermoproteus
Thermus
AnacystisBacillus
Physarum
CrithidiaTetrahymena
ProrocentrumSaccharomycesOryza
Homo
Drosophila
Streptomyces
EUCARYA
ARCHAEA
EUBACTERIA« BACTERIA »
?
Only Bacteria
Bacteria and Eucarya
Bacterial Genomes:Circular dsDNA
Here G+C = 50%
The G+C content is a genome structure
Life History Traits and Genome Structure
Aerobiosis and G+C Content in Bacteria
J.R. LobryUniversité Claude Bernard - Lyon I
CNRS UMR 5558 & INRIA Helix
FRANCE
Aerobiosis and G+C Content in Bacteria
AerobicAnaerobic
Naya et al. (2002) J. Mol. Evol., 55:260
Aerobiosis and G+C Content in Bacteria
AerobicAnaerobic
Naya et al. (2002) J. Mol. Evol., 55:260
Why?
Metabolic cost of amino-acids in Aerobiosis
Akashi & Gojobori (2002) PNAS, 99:3695
11.7 ATP
38.3 ATP11.7 ATP
52.0 ATP
15.3 ATP14.7 ATP
27.3 ATP
27.3 ATP
From amino-acid cost to Protein cost
Akashi & Gojobori (2002) PNAS, 99:3695
Pro
tein
cos
t in
AT
P
Protein concentration in cells
So what?
The growth of genomic data
But available fossil DNA is < 0.00013 109 years...
All data are here
Dataset
• ~300 bacterial species
• ~1,000,000 proteins
• ~100,000,000 amino-acids
Akashi (2002)
Naya (2002)
Interpretation
Aerobic bacteria have a higher genomic G+C content than anerobic bacteria because this induces an average protein composition which is less expensive in aerobic conditions
Aerobiosis and G+C Content in Bacteria
Life History Traits and Genome Structure
J.R. LobryUniversité Claude Bernard - Lyon I
CNRS UMR 5558 & INRIA Helix
FRANCE