Cloning, sequencing, and function of sanF: A gene involved in nikkomycin biosynthesis of Streptomyces ansochromogenes

A 111-bp DNA fragment related to nikkomycin biosynthesis of Streptomyces an sochromogenes 7100 was obtained with the method of reverse genetics. Then, a 2.2-kb DNA fragment was cloned from the DNA library of S. ansochromogenes 7100 by using the 111-bp fragment as a probe, Sequence analysis showed tha t the fragment contains one complete open reading frame (ORF) that encodes a 219-amino acid (aa) protein, and this gene was designated sanF (GenBank A ccession No. AF223971). The function of the sanF gene was studied by a stra tegy of gene disruption, and the resulting sanF mutants lost the ability to synthesize biologically active nikkomycin, indicating that sanF is essenti al for nikkomycin biosynthesis.