Fig 3.

pyrF deletion in strain HTA426. (A) Gene organization of the pyr cluster (GK1147 to GK1157) in G. kaustophilus HTA426 and schematic diagram of construction of mutant strain MK54. The 0.6-kb region of pyrF was deleted by reciprocal crossovers. Probes 1 and 2 were used for Southern hybridization. (B) Southern hybridization to verify the correct deletion. Chromosomal DNA was digested with HincII. (C) Analysis of uracil auxotrophy. Strain HTA426, mutant strain MK54, and pyrF-complemented MK54 (MK54c) were incubated on MM plates with and without 10 mg/liter uracil.