Relative quantification by mass spectrometry-based label-free quantification of PSI and PSII subunits in affinity chromatography eluates is shown. All quantifications are normalized to the content in psbs KO. Relative enrichment in PSBS-expressing genotypes (N-His-PSBS/C-His-PSBS) is also shown. LHCBM, LHCB4, and LHCB5 include multiple polypeptides that were not individually distinguished, as detailed in “Materials and Methods.” n.d., Protein not detected. All data are expressed as averages ± se of three independent replicates.