In frame deletion of argB in S. coelicolor A3(2) and mutant complementation by polP. A. Schematic representation for construction of CX2 mutant; B. PCR identification of CX2 mutant. As ca. 0.4-kb of argB was in frame deleted, the wild type of S. coelicolor A3(2) gives a 1.1-kb product, and the products of CX2 mutant are 0.68-kb in size. C. Plate grown experiments for CX2 mutant and its complemented strains, S. coelicolor A3(2) wild type (1) and CX2 mutant complemented by argB (S. cacaoi) in pJTU4713 (5) were used as positive controls, and CX2 mutant containing empty vector, pJTU2170, was used as negative control (3); CX2 mutant (2) and its complemented strain by polP in pJTU2870 (4) were indicated as parallels.