Table 1.

Bacterial strains and plasmids used in this study

Strain or plasmid	Genotype or relevant characteristic	Reference or source
E. coli
XL1-Blue	RecA1, endA1, gyrA96, thi-1, hsdR17, supE44, relA1, lac, [F′, proAB, lacIqZΔM15, Tn10 (tetr)]	20, Stratagene
M15(pREP4)	Lac, ara, gal, mtl, recA+, uvr+, [pREP4, lacI, kanr]	21
Plasmids
pQE30	High copy His-tag expression vector	Qiagen
pNCO113	High copy expression vector	ATTC, PTA-852
pQEygbParakom		This study
pNCOygbPara		This study