Cells: wild-type E.coli K12 Experiment: - grown in minimal medium M9, as described in [Lu, Vogel, Wang, Yin, Marcotte, Nature Biotech 2007] CYS modification: NO Mass spectrometry: LC/LC-MS/MS on LTQ-Orbitrap Analysis: SEQUEST (Bioworks) Peptide/ProteinProphet