FIG. 4.

SDS-polyacrylamide gel electrophoresis of proteins from E. coli CAG2242 and SR-199 (A) and amino acid sequence of the NH₂ terminus of the induced protein in E. coli SR-199 (B). (A) E. coli CAG2242 and SR-199 were cultured in the absence and presence of 4 mM spermidine, respectively, for 24 h. SDS-polyacrylamide gel electrophoresis was performed with 20 μg of protein. The arrow indicates the induced protein. (B) The amino acid sequence determined by Edman degradation is underlined. Accordingly, the induced protein was identified as a glycerol kinase, whose amino acid sequence is shown in panel B.