Fig. 1

Mapping and sequencing LysC protease resistant fragments of R2Bm protein. a R2Bm protein was digested with LysC protease and analyzed by SDS-PAGE. Major observed bands were designated LA-LI. The triangle represents a time course of LysC digestion. The molecular weight (MW) marker values are given. b Identification of proteolytic fragments of R2Bm protein. Bands from panel A were cut out, further processed, and analyzed by nano-LC-ESI-MS/MS sequencing. The N-terminal of the band producing fragment was identified by acetylation. Internal peptides were sequenced as well. The y and b ions that identified the N-terminal end are indicated. Symbols: * = acetylation; @ = oxidation;! = carbamidomethylation. The spectrum is given in the supplemental data. c Map of the band purified R2Bm fragments. A detailed diagram of the R2Bm open reading frame (ORF) is given along with an amino acid ruler. The boundaries of the R2Bm proteolytic resistant fragments LA-LI are mapped below, along with the amino acid and primary sequence position of the first amino acid of the fragment. The C-terminal ends were not exactly pinpointed but were roughly determined using the apparent MW from the SDS-PAGE gel and by the coverage of internal peptides sequenced by nano-LC-ESI-MS/MS. The major earliest and latest appearing gel bands are roughly grouped together in the map. Abbreviations: zinc finger (ZF) and restriction-like endonuclease (RLE)