Figure 1.

Location and deduced primary sequence of the zinc finger motif of the Ros protein and sites of amino acid substitution. The nucleotide sequence published previously (12) has been deposited in GenBank (accession no. M65201). (a) The mutations placed at positions 82 and 92 with alanine substitutions are indicated below the wild-type amino acid sequence. (b) Expression and purification of wild-type and mutant Ros proteins. Proteins from total cellular extracts and purification were analyzed in a SDS/12% polyacrylamide gel and stained with Coomassie blue. Lanes: 1, molecular weight standards; 2, 4, and 6, total cellular extracts (∼20 μg per lane) of E. coli BL21(DE3) containing pUCD4401, pUCD4401C82A, and pUCD4401H92A, respectively [these plasmids are the respective wild-type and mutant ros genes cloned into pET-3a (25)]; 3, 5, and 7, approximately 2 μg of purified Ros, RosC82A, and RosH92A, respectively.