Table 1.

Summary of BSS expression constructs used in this study

Plasmid name	Vector used	Gene inserted	Cloning sites	Description
pET28_F	pET28b	tutF	NdeI/EcoRI	Expression of BSS-γ subunit with a N-terminus His6 tag
pET28_G	pET28b	tutG	NdeI/HindIII	Expression of BSS-β subunit with a N-terminus His6 tag
pET28_D	pET28b	tutD	NdeI/HindIII	Expression of BSS-α subunit with a N-terminus His6 tag
pET-Duet_F	pET-Duet	tutF	NcoI/HindIII	Expression of BSS-γ subunit with no tag (negative control for monitoring BSS α subunit expression in cell-free extract)
pET-Duet_D_F	pET-Duet	tutD tutF	NdeI/KpnI NcoI/HindIII	Expression of BSS-α and γ subunits with a C-terminus His6 tag on the α subunit
pRSF-RSF_G	pRSF-Duet	tutG	NdeI/XhoI	Expression of BSS-β subunit with no tag
pET-Duet_D_F_stop	pET-Duet	tutD	NdeI/KpnI	Expression of BSS-α subunit with a C-terminus His6 tag
pET-Duet_D_F_C9S	pET-Duet	tutD tutF_C9S	NdeI/KpnI NcoI/HindIII	Expression of BSS-α and γ subunits with a subunit carrying a C-terminus His6 tag and γ subunit a C9S mutation
pRSF-Duet_G_C29S	pRSF-Duet	tutG_C29S	NdeI/XhoI	Expression of BSS-β subunit with a C29S mutation
pACYC-Duet_F_C9S	pACYC-Duet	tutF_C9S	BamHI/XhoI	Expression of BSS-γ subunit with a N-terminus His6 tag and a C9S mutation
pET28_G_C29S	pET28b	tutG_C29S	NdeI/HindIII	Expression of BSS-β subunit with a N-terminus His6 tag and a C29S mutation