Natural competence in bacteria Flashcards
1
Q
What is natural competence?
A
The ability of a cell to alter its genetics by taking up extracellular DNA from its environment in the process called transformation
2
Q
Describe E. coli
A
Human colon bacteria 2x10^10 new E. coli every day 9 million mutations per day per host Gram-negative Model organism 4.6 Mbps 4300 genes
3
Q
Describe b. subtilus
A
Gram-positive rod Obligate anaerobe Spore former Soil bacterium 4.3 Mbps 4100 genes Naturally competent Thick peptidoglycan layer Cell wall ~10nm thick Only proteins <25 kDa can permeate Pseudo type IV pilus system Nucleases fragment DNA to attach to the pilus system 3' end goes through ss and is remade ds
4
Q
Describe Neisseria
A
Gram-negative diplococci Microaerophillic metabolism Human commensal 2 Mbps 1900 genes Naturally competent Preference for own DNA
5
Q
Describe H. pylori
A
Gram-negative curved rod ~1μm
Unusual microaerophilic metabolism
Obligate human commensal
Preference for the stomach lining
1.7 Mbps
1600 genes
Every carrier has a unique strain
High urease activity to create a cloud of ammonia to live in
Continually takes up DNA and modifies its own genome
Type IV secretion system and DNA translocase
