Two new tailoring enzymes, a glycosyltransferase and an oxygenase, involved in biosynthesis of the angucycline antibiotic urdamycin A in Streptomyces fradiae Tü2717 This paper is dedicated to Professor Heinz Floss, a pioneer in the field of antibiotics, on the occasion of his 65th birthday. The GenBank accession numbers for the sequences reported in this paper are AF164960 and AF164961.