TABLE 1.

Strains and plasmids

Strain or plasmidDescriptionSource or reference
E. coli strains
    DH5αF′KanCloning strain, KanrInvitrogen
    BL21(DE3)Expression strainStratagene
B. bronchiseptica strains
    RB50Wild-type strainJ. Miller
    RBB4Internal bhuR truncation in RB50S. K. Armstrong (unpublished)
Plasmids
    pGEM-TPCR fragment cloning vector, AmprPromega
    pET21aExpression vector, AmprNovagen
    pMOX13PCR-amplified DNA fragment encoding bhuR ligated into pGEM-TThis study
    pMOX14.1NdeI/XhoI fragment from pMOX13 encoding bhuR ligated into pET21aThis study