... used for induction (instead of 200 lm).With the TorA-GFP export assays, TorA-GFP wasinduced with arabinose for 2 h, after which the arabi-nose was removed and the cells incubated with IPTG for ... respect, our data differ at first sight from those described in [25], where several TatA⁄ TatBmutants were found to exhibit export efficiencies thatwere much-reduced. For example, the TatA F20Aand G21A ... essential for Tat function. Taking these previ-ous reports into consideration, the logical conclusion isthat several residues (F20, G21 in TatA, G21, P22,P26 in TatB) are probably important for...