Transcription of B. subtilis glucokinase operon. (A) Glucokinase operon is located between chromosomal 2569.795 and 2572.793 kb, as is available in the SubtiList database . β-galactosidase assays of the transcriptional glucokinase operon – lacZ fusions were determined quantitatively as described in materials and methods. Average value of β-galactosidase activity (U/mg protein) is presented from two independent experiments. β-galactosidase activity (bluish green colour) was also monitored in vivo using LB plates containing X-Gal. (B) Northern blot of glucokinase transcript with a probe localized within glcK.