Fig 8. Essentiality of proteins in complexes.

Distribution of essential genes among those from E. coli (Hu et al. (A) and EcoCyc (B), respectively) and M. pneumoniae (C). The fraction of essential genes within protein complexes was determined for each complex set. In E. coli, essential protein complexes are enriched for essential proteins. By contrast, complexes with non-essential proteins are over-represented in the genome-reduced Mycoplasma pneumoniae. Each distribution is expressed as binned log₂ ratios of observed over expected frequency. Values indicate observed frequency above or below random results (= 1), respectively.