title: Chemical characterisation of disruptants of the Streptomyces coelicolor A3(2) actVI genes involved in actinorhodin biosynthesis.
abstract: The actVI genetic region of Streptomyces coelicolor A3(2) is part of the biosynthetic gene cluster of actinorhodin (ACT), the act cluster, consisting of six ORFs: ORFB, ORFA, ORF1, ORF2, ORF3, ORF4. A newly devised method of ACT detection with a combination of HPLC and LC/MS was applied to the analysis of the disruptants of each ORF. ACT was produced by those of ORFB, ORFA, ORF3, and ORF4. Instead of ACT, the ORF1 disruptant produced 3,8-dihydroxy-1-methylanthraquinone-2-carboxylic acid (DMAC) and aloesaponarin II as shunt products. The ORF2 disruptant gave 4-dihydro-9-hydroxy-1-methyl-10-oxo-3-H-naphtho-[2,3-c]-pyran-3-(S)-acet ic acid, (S)-DNPA. These results support our previous proposal for stereospecific pyran ring formation in the biosynthesis of ACT, most importantly suggesting that the actVI-ORF2 product would recognize (S)-DNPA as a substrate for stereospecific reduction at C-15. The disruptant of ORFA produced (S)-DNPA together with ACT, suggesting that actVI-ORFA might play a role such as stabilising the multicomponent, type II PKS complex.
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Taguchi
authors.forename: K
authors.initials: K
authors.lastname: Itou
authors.forename: Y
authors.initials: Y
authors.lastname: Ebizuka
authors.forename: F
authors.initials: F
authors.lastname: Malpartida
authors.forename: D A
authors.initials: DA
authors.lastname: Hopwood
authors.forename: C M
authors.initials: CM
authors.lastname: Surti
authors.forename: K I
authors.initials: KI
authors.lastname: Booker-Milburn
authors.forename: G R
authors.initials: GR
authors.lastname: Stephenson
authors.forename: K
authors.initials: K
authors.lastname: Ichinose
mesh_terms: D000880:Anthraquinones / Q000032:analysis / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003470:Culture Media; D015964:Gene Expression Regulation, Bacterial; D013058:Mass Spectrometry / Q000379:methods; D005810:Multigene Family; D009154:Mutation; D009281:Naphthalenes / Q000032:analysis / Q000378:metabolism; D011714:Pyrans / Q000032:analysis / Q000378:metabolism; D013302:Streptomyces / Q000235:genetics* / Q000378:metabolism*; D000095622:Benzoisochromanequinones
chemical_list: D000880:Anthraquinones; D001426:Bacterial Proteins; D003470:Culture Media; D009281:Naphthalenes; D011714:Pyrans; C099619:3,8-dihydroxy-1-methylanthraquinone-2-carboxylic acid; C408422:4-dihydro-9-hydroxy-1-methyl-10-oxo-3-H-naphtho-(2,3-c)-pyran-3-acetic acid; C092187:aloesaponarin II; C013390:actinorhodin; D000095622:Benzoisochromanequinones