Fig. 5

SDS-PAGE of IM328_ck and IM328_sqr. Stacking gel of 5 % polyacrylamide (pH 6.8) and separating gel of 12 % polyacrylamide (pH 8.8) were used, and 20 µL protein extracts were loaded for electrophoresis at the low temperature. The gels containing possible target bands of similar molecular weight were recovered for mass spectrometry, and the samples were numbered 1 to 5, of which samples 1, 2, and 3 (marked by #) contained peptide fragments of interest Sqr. The details are summarized in Additional file 1: Table S3. IM328_ck: IM328_ck strain as control; IM328_sqr: IM328_sqr strain; M: protein marker