TABLE 1.

Bacterial strains, cosmids, and plasmids used in this study

Strain, plasmid, or cosmid	Description	Antibiotic resistancea	Reference(s) or source
Escherichia coli strains
BW25113/pIJ790 strain	Host for λRED-mediated PCR targeting system	Camr	37, 46
ET12567/pUZ8002 strain	Nonmethylating host (lacking genes dam, dcm, and hsdM); carries the pUZ8002 plasmid that encodes the machinery for the conjugal transfer of DNA into Streptomyces	Camr, Tetr, Kanr	36, 47
Streptomyces scabiei strains
ΔtxtA/pRLDB51-1 strain	Strain containing a deletion of the txtA gene and carrying the cfaR (scab79591) overexpression plasmid pRLDB51-1	Thior, Aprar	14
ΔtxtA Δcfa6 strain	Strain containing a deletion of the txtA and cfa6 genes	Hygr, Aprar	14
ΔCYP107AK1 strain	ΔtxtA/pRLDB51-1 derivative containing a deletion of the CYP107AK1 (scab79691) gene	Thior, Aprar, Hygr	This study
Plasmid or cosmid
pIJ10700	Template for PCR amplification of the hyg-oriT cassette used for PCR targeting	Hygr	46
Cosmid 1770	SuperCos1 derivative containing the S. scabiei CFA biosynthetic gene cluster	Ampr, Kanr	14
1770/ΔCYP107AK1	Cosmid 1770 derivative in which the CYP107AK1 gene was replaced with the hyg-oriT disruption cassette	Ampr, Kanr, Hygr	This study

^aCam^r, Tet^r, Kan^r, Thio^r, Apra^r, Hyg^r, and Amp^r indicate chloramphenicol, tetracycline, kanamycin, thiostrepton, apramycin, hygromycin B, and ampicillin resistance, respectively.