The ‘bag of enzymes concept’

Bacteria have been regarded through other biologists as extremely simple organisms, with no cellular or subcellular structure. As can be seen from other sections of this book this is far from the case.  Protein targeting, post-transcriptional processing and post-translational processing are all part of the biochemistry of the bacteria. However our detailed knowledge of this biochemistry also allows us to manipulate translation and transcription for the overproduction of proteins. An Escherichia coli cell can be manipulated to make more than 15% of all its protein as a single recombinant form and as such E. coli is the primary expression system for most protein studies from crystallography through to Michaelis–Menten kinetics.