Amino acid 321 within second coiled-coil region determines chain length. A, effect of site-directed mutants in 9882-80 Wzz2 protein. For each panel, the top panel shows LPS profile of strains, whereas the bottom panel depicts expression levels of Wzz2 proteins. The lanes depict the DΔM containing the vectors as follows: lane 1, pHERD30T; lane 2, pPA103 wzz2; lane 3, p9882-80 wzz2; lane 4, p9882-80 A48V; lane 5, p9882-80 D241G; lane 6, p9882-80 K321T; lane 7, p9882-80 V404A. B, changing Wzz2 protein at position 321 affects chain length. The lanes depict the DΔM containing the vectors as follows: lane 1, pPA103 wzz2; lane 2, pPA103 T321K; lane 3, p9882-80 wzz2; lane 4, p9882-80 K321T. C, amount of Wzz2 protein does not affect chain length produced. Lanes 1 and 2 are the DΔM expressing pPA103 wzz2, and lanes 3 and 4 indicate pPA103 T321K. Amounts of arabinose shown are 0.2% (lanes 1 and 3) versus 2.0% (lanes 2 and 4).