TABLE 1

Bacterial strains and plasmids used in this study

Strain or plasmidRelevant genotypea or functionSource or reference
Streptococcus mutans strains
    UA159Wild typeLaboratory stock
    JL12 ΔspxA1spxA1::Spr21
    JL13 ΔspxA2spxA2::Ermr11
    JL21 ΔspxA1 ΔspxA2spxA1::Spr spxA2::Ermr11
    JL32 spxA1G52RSpxA1G52RThis study
    JL33 spxA2G52RSpxA2G52RThis study
    JL34 ΔspxA1 spxA2G52RspxA::Spr SpxA2G52RThis study
Other bacterial strains
    B. subtilis MH5636His-tagged RNAP42
    E. coli BL21(DE3)Expression host strainNew England BioLabs
    E. coli DH5αExpression host strainInvitrogen
    S. gordonii DL-1Wild typeLaboratory stock
Plasmids
    pET16B-SpxA1His-tagged SpxA1This study
    pET16B-SpxA2His-tagged SpxA2This study
    pSU20erm-lacGCompetency control27
    pMSP3535Expression in S. mutans31
    pMSP3535-SpxA1-HisExpression of SpxA1-HisThis study
    pMSP3535-SpxA2-HisExpression in SpxA2-HisThis study
    pMALc2x-SpxA1MBP-tagged SpxA1This study
    pMALc2x-SpxA1G52RMBP-tagged SpxA1G52RThis study
  • a Spr, spectinomycin resistance; Ermr, erythromycin resistance.