1. Replicons have genes for: DNA polymerase Transcription factors
3 chromosomes
Main chromosome 2,015 kb
191 kb replicon
366 kb replicon
Replicons have genes for:
DNA polymerase
Transcription factors
Mineral uptake (K, PO4)
Cell division
The genome has many insertion sites for foreign genes
Bacteriorhodopsin:
Protein + retinal
Amax 280 UV, 570 green nm
energy for proton transport and phosphorylation without photosynthesis!
Halobacterium salinarum
archaea/halobacterium/halobacteria_1.jpg
Aerobic Respiration
Up to 5 M (25% NaCl)!
Great Salt Lake, Utah
Red Sea, Asia Minor

2. Hint: it reflects the other colors of the spectrum
Periplasmic
space
Cell
Membrane
Retinal
lsu.epfl.ch/sh/bR_full.pdf
Bacteriorhodopsin absorbs green from the visible spectrum, so what color is the pigment?
Cytoplasm
Hint: it reflects the other colors of the spectrum
Alam/publications/PNAS96-ZHANG.pd

3. How do Archaea tolerate the heat?
Proteins stabilized by more ionic bridges between amino acid r-groups and more-hydrophobic core amino acids
Heat shock protein (chaperonins) refold denatured proteins…Pyrococcus 121°C for 1 hour!
DNA depurination reduced by presence of 2,3-diphosphoglycerate.
DNA supercoiling by reverse gyrase reduces denaturation
Sac7d in Sulfolobus is a minor groove protein increases the melting temperature by 40°C
Histone-like proteins help stabilize DNA as well
Heat-resistant di-bi-phytanyl diether lipid membranes (monolayer) prevent delamination of membrane

4. Cell Membrane Structure
Composed of diglycerides
R group may be phosphate, sulfate, or sugar
Long chain branched hydrocarbon (not fatty acid)
Hydrocarbons may be C20 or C40
If C20, the membrane is a bilayer: O R
If C40, the membrane is a monolayer O R
In some species, the membrane is a mixture of both C20 and C40 diglycerides forming a mixed mono-/bi-layer. The C40 diglycerides prevent the bi-layer from de-laminating!

5. Thermus aquaticus Gram negative eubacterium Thermophile isolated from
Not all thermophiles are archaeons
Thermus aquaticus
Gram negative eubacterium
Thermophile isolated from
Yellowstone Hot Spring
Optimum temperature 85°C
Stability of macromolecules excellent
Enzymes for research or commercial use--Taq polymerase is the enzyme of PCR (Polymerase Chain Reaction)
Lives near cyanobacteria which feed CH2O to Thermus
ag_franceschi/franceschi-projects-30S.html