Towards the minimal proteome of life: Proteome profiles of Bacillus subtilis vegetative cells and spores

The method of N metabolic labelling of enabled mass spectrometric quantification of relative protein levels in the vegetative cells and the spores of this model organism. A total of 1501 proteins have been identified from the combined spore and vegetative cell samples. From these 1086 proteins have been relatively and reproducibly quantified between spores and vegetative cells. Of the quantified proteins, 60% are common to the vegetative cells and spores, indicating that spores host a minimal set proteins sufficient for the resumption of metabolism upon completion of germination. The shared proteins represent, the most basic ‘survival kit’ for life on earth that is known thus far.