TABLE 1.

GAS strains used in this study

Strain name	Description	Reference or source
MGAS6180	Serotype M28 clinical GAS isolate that has been genome sequenced	29
M28 + pDCBB	MGAS6180 containing the empty shuttle vector pDCBB	21
M28ΔFasX + vector	MGAS6180 derivative in which the fasX gene has been replaced with a spectinomycin resistance cassette; also contains empty shuttle vector pDCBB	21
M28ΔFasX + pFasX	M28ΔFasX containing the pDCBB derivative pFasX, which contains a wild-type fasX allele downstream of the natural promoter	21
M28ΔFasX + pFasX.UC.loop	M28ΔFasX containing the pDCBB derivative pFX.C71/73G, in which the C nucleotides at positions 71 and 73 have been mutated to G	This work
M28ΔFasX + pFasX.ska.loop	M28ΔFasX containing the pDCBB derivative pFXC45/46G, in which the C nucleotides at positions 45 and 46 have been mutated to G	This work
M28ΔprtF1 + vector	MGAS6180 derivative in which the prtF1 gene has been replaced by a spectinomycin resistance cassette; also contains empty vector pDCBB	This work
M28ΔprtF2 + vector	MGAS6180 derivative in which the prtF2 gene has been replaced by a spectinomycin resistance cassette; also contains empty vector pDCBB	This work