bacterial immune system? how developed / nil !? - recombinant bacteria tolerance? (Dec/17/2007 )

hii..
me has a verrry basic question.. some how missed knowing this..

how is and how good is a bacterial immune system..?? how does it work?

also, why don't bacteria chop off the proteins that r synthesized within them.. with recombinant DNA.. ?

lemme know plss...
thankuu!!

I don't know much about the bacterial "immune" system really, except that restriction enzymes are there to cut up foreign DNA. I presume the bacteria restriction enzymes recognise sites not present in their own DNA, but in bacteriophage or other bacterial species. The only organism that is a pathogen for bacteria would be bacteriophages but there would be competion between different bacterial species for resources so it depends if you count scavenger molecules as "immune" components. Maybe place your post in the microbiology forum section. E. coli for cloning/expression systems are modified to avoid DNA recombination and probably degradation of proteins. Although some overexpressed proteins are toxic so are difficult to express under certain circumstances.

Hope that helps?
Ceri