FIG. 2.

lpsS mutants show reduced LPS sulfotransferase activity in vitro. (A) Extracts prepared from the wild type and lpsS mutants were assayed for sulfotransferase activity as described in Materials and Methods. Lane 1, no extract (N.E.); lane 2, strain Rm1021 (WT, wild type); lane 3, lpsS::pDW33 mutant; lane 4, lpsS::pDW33 harboring pMB393 (Vect., vector control); lane 5, lpsS::pDW33 harboring plasmid pDKR161 (pMB393/lpsS). (B) Quantification of sulfotransferase activity in lpsS mutant extracts. Sulfotransferase activity was calculated by measuring the incorporation of sulfate into LPS using a phosphorimager and dividing by the amount of protein in the extract. Lanes are the same as for panel A. Error bars represent standard deviations.