FIG. 2.

Comparison of RdxA and RdxB amino acid sequences and production of RdxA and RdxB in in vitro- and in vivo-isolated Mtz^r C. jejuni 81-176 mutants. (A) ClustalV alignment of the amino acid sequences of RdxA and RdxB from C. jejuni 81-176. Asterisks (*) indicate identical residues, semicolons (:) indicate highly conserved residues, and periods (.) indicate weakly conserved residues. Plus signs (+) above residues of RdxA indicate residues changed by point mutations in Mtz^r C. jejuni isolates after in vitro or in vivo growth. (B) Immunoblot analysis of RdxA and RdxB production in whole-cell lysates of Mtz^r C. jejuni 81-176 isolates with point mutations in rdxA isolated after in vitro or in vivo growth. The wild-type strain is 81-176 Sm^r (DRH212) (WT), and the cat::rpsL mutants used in the immunoblots are DAR521 (81-176 Sm^r rdxA::cat-rpsL) and DAR562 (81-176 Sm^r rdxB::cat-rpsL), respectively. Most Mtz^r isolates are identified by the type of change occurring in the protein sequence after spontaneous mutation. T-52C refers to an Mtz^r isolate with a nucleotide change occurring 52 bases upstream of the rdxA start codon. ΔrdxA-rdxB refers to an Mtz^r isolate with a deletion of DNA encompassing the 3′ end of rdxA through the 5′ end of rdxB.