Expression of the flagellar operons in the FliA-overproducing conditiona baflllehlDeCb pTrc99C pKKOPA99C Activity with plasmid : Class 1 flhD-lac 1 0.99 : : lac Class 2 fliA-lac + : : TnlO 1 3.58 0.18 3.34 0.18 13.3 0.09 17.6 0.13 6.00 0.16 19.1 0.12 14.3 0.12 0.19 1 0.17 1 0.11 1 0.15 1 0.18 1 0.13 1 0.15 + : : TnlO + : : TnlO + : : TnlO + : : TnlO + : : TnlO + : : TnlO flgA-lac flgB-lac flhB-lac fliE-lac fliF-lac fliL-lac Class 3 + 1 9.77 : : TnlO 0.18 5.70 fliC-lac flgK-lac fliD-lac + 1 10.0 : : TnlO 0.19 7.03 + 1 12.2 : : TnlO 0.12 4.17 + 1 10.4 : : TnlO 0.10 9.18 + 1 8.74 : : TnlO 0.22 6.53 a KK1004 ( flhDC + ) or KK2040 ( flhD : : TnJO ) carrying the lac fusions with the flagellar operons were transformed with the respective plasmids , and the activity of 0-galactosidase was assayed with each transformant after induction for 2 h with IPTG .