FIG 7.
Pro-HybCHyaB retains dependence on the HybD protease. (A) A native PAGE gel stained for hydrogenase activity using benzyl viologen-triphenyl tetrazolium chloride is shown. Samples of crude extracts (50 μg of protein) derived from MC4100 and CB16 (ΔhyaD ΔhybC ΔhycE ΔhyfB-hyfH) either lacking a plasmid or, in the case of CB16, carrying a plasmid encoding pro-HyaBHybC or pro-HybCHyaB were loaded on the gel. (B) The same samples used for panel A were separated in a 12.5% (wt/vol) SDS gel and after transfer to nitrocellulose were challenged with anti-Hyd-2 antiserum. The migration positions of the respective polypeptides are indicated at the right.