Table III.

Bacterial strains and plasmids

Strain or Plasmid	Relevant Characteristics	Source
Bacterial strains
HMS174 (DE3)	F-recA1 hsdR(rK12- mK12+) RifR	Novagen (Madison, WI)
BL21trxB (DE3)	F-ompT hsdSB (rB- mB-) gal dcm trxB15::kan	Novagen
Plasmids
pET23a(+)	Expression vector providing a C-terminal hexahistidine tag	Novagen
pET23-Tkl	Plasmid expressing a C-terminally His-tagged pseudomature TK	This study
pET32a(+)	Expression vector providing a thioredoxin domain, hexahistidine tag, an S-Tag, and an enterokinase cleavage site	Novagen
pET32-Tkl7otp	Plasmid expressing a thioredoxin-TK-fusion protein	This study
pET32-ZMTK-	Plasmid expressing an engineered thioredoxin-TK-fusion protein	This study
Tb