title: A regulatory gene (ECO-orf4) required for ECO-0501 biosynthesis in Amycolatopsis orientalis.
abstract: ECO-0501 is a novel linear polyene antibiotic, which was discovered from Amycolatopsis orientalis. Recent study of ECO-0501 biosynthesis pathway revealed the presence of regulatory gene: ECO-orf4. The A. orientalis ECO-orf4 gene from the ECO-0501 biosynthesis cluster was analyzed, and its deduced protein (ECO-orf4) was found to have amino acid sequence homology with large ATP-binding regulators of the LuxR (LAL) family regulators. Database comparison revealed two hypothetical domains, a LuxR-type helix-turn-helix (HTH) DNA binding motif near the C-terminal and an N-terminal nucleotide triphosphate (NTP) binding motif included. Deletion of the corresponding gene (ECO-orf4) resulted in complete loss of ECO-0501 production. Complementation by one copy of intact ECO-orf4 restored the polyene biosynthesis demonstrating that ECO-orf4 is required for ECO-0501 biosynthesis. The results of overexpression ECO-orf4 on ECO-0501 production indicated that it is a positive regulatory gene. Gene expression analysis by reverse transcription PCR of the ECO-0501 gene cluster showed that the transcription of ECO-orf4 correlates with that of genes involved in polyketide biosynthesis. These results demonstrated that ECO-orf4 is a pathway-specific positive regulatory gene that is essential for ECO-0501 biosynthesis.
authors.affiliation: School of Biotechnology, East China University of Science and Technology, Shanghai, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Shen
authors.forename: He
authors.initials: H
authors.lastname: Huang
authors.forename: Li
authors.initials: L
authors.lastname: Zhu
authors.forename: Minyu
authors.initials: M
authors.lastname: Luo
authors.forename: Daijie
authors.initials: D
authors.lastname: Chen
mesh_terms: D000192:Actinomycetales / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D005231:Fatty Acids, Unsaturated / Q000096:biosynthesis* / Q000235:genetics; D006146:Guanidines; D008969:Molecular Sequence Data; D005810:Multigene Family; D017422:Sequence Analysis, DNA
chemical_list: C515838:13-hydroxy-2,12,14,16,22-pentamethyl-28-(N-methyl-guanidino)-octacosa-2,4,6,8,10,14,20,24-octaenoic acid (2-hydroxy-5-oxo-cyclopent-1-enyl)-amide; D005231:Fatty Acids, Unsaturated; D006146:Guanidines
keywords: Amycolatopsis orientalis; ECO-0501; LAL-family; Positive regulator