Figure 1
Construction and activity of a quintuple mutant YidC-5S. (a) Structure and topology of YidC-5S (PDB 3WVF). The locations of the 5 serine mutations are highlighted with yellow dots and are all located in the upper part of the hydrophobic slide of YidC; TM3 is coloured in red, TM4 in yellow and TM5 in gold. (b) Colony growth of MK6 cells with plasmids encoding the cysteine-less YidC0 (lane 1, 3, 5) or the YidC-5S mutant (lane 2, 4, 6). The cells were either grown on plates containing 0.2% arabinose that allow expression of the chromosomal yidC (lanes 1, 2), or on plates containing 0.4% glucose that repress the chromosomal yidC (lanes 3, 4), or on plates with glucose and 1 mM IPTG that induce the plasmid-encoded yidC (lanes 5, 6). Serial dilutions (tenfold, indicated on right margin) of the respective cultures were applied onto the agar plates and incubated at 37 °C overnight.
