title: The post-polyketide synthase modification steps in the biosynthesis of the antitumor agent ansamitocin by Actinosynnema pretiosum.
abstract: The functions of six genes in the ansamitocin biosynthetic gene cluster of Actinosynnema pretiosum have been investigated by gene inactivation and chemical analysis of the mutants. They encode a halogenase (asm12), a carbamoyltransferase (asm21), a 20-O-methyltransferase (asm7), a 3-O-acyltransferase (asm19), an epoxidase (asm11), and an N-methyltransferase (asm10), respectively, and are responsible for the six post-PKS modification steps in ansamitocin formation. Several of the enzymes have relaxed substrate specificities, resulting in multiple parallel pathways in a metabolic grid, albeit with a preferred sequence of reactions as listed above.
authors: Department of Chemistry, Box 351700, University of Washington, Seattle, WA 98195-1700, USA.
authors: Peter
authors: P
authors: Spiteller
authors: Linquan
authors: L
authors: Bai
authors: Guangdong
authors: G
authors: Shang
authors: Brian J
authors: BJ
authors: Carroll
authors: Tin-Wein
authors: TW
authors: Yu
authors: Heinz G
authors: HG
authors: Floss
mesh_terms: D000192:Actinomycetales / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism*; D000903:Antibiotics, Antineoplastic / Q000096:biosynthesis*; D008453:Maytansine / Q000031:analogs & derivatives* / Q000378:metabolism*; D009097:Multienzyme Complexes / Q000378:metabolism*
chemical_list: D000903:Antibiotics, Antineoplastic; D009097:Multienzyme Complexes; D008453:Maytansine; C015682:ansamitocins