Fig. 2

Western blot detection of small proteins. Recombinant Synechocystis 6803 cells carrying the genes of interest (goi) under control of the petE promoter on pVZ322 vector were collected before (−) or 24 h after induction of gene expression (+) for the extraction of total proteins. FLAG-tagged superfolder GFP (sfGFP) under the control of the petJ promoter [37] served as positive control, a WT strain carrying an empty pVZ322 vector was used as negative control (n.c.). Theoretical protein masses are listed in Table 3. Two gels were run in parallel. a Proteins (30 μg) were separated on a 15% (w/v) SDS polyacrylamide gel and subjected to colloidal Coomassie G-250 staining as a loading control. b Immunoblot with the same loading order probed with specific ANTI-FLAG® M2-Peroxidase (HRP) antibody