title: hmgA, transcriptionally activated by HpdA, influences the biosynthesis of actinorhodin in Streptomyces coelicolor.
abstract: Homogentisate 1,2-dioxygenase (HmgA) converts homogentisate to maleylacetoacetate in the pathway of tyrosine catabolism in living organisms. Studies published to date have not elucidated the transcriptional regulation of hmgA and its biological function in Streptomyces spp. Here it is shown that the transcription of hmgA in Streptomyces coelicolor was activated by HpdA, an AsnC-type activator, in the presence of tyrosine. Disruption of hmgA led to enhanced production of diffusible brown pigment, suggesting that hmgA is required for tyrosine catabolism in Streptomyces coelicolor. The production of actinorhodin in the hmgA disruption mutant was several fold higher than that in the wild-type strain (M145), indicating that hmgA of tyrosine catabolism correlates with actinorhodin biosynthesis. Furthermore, S1 mapping showed that the transcription of actII-ORF4, a pathway-specific activator gene of actinorhodin biosynthesis, was increased in the hmgA disruption mutant. These results reveal the transcriptional regulation of hmgA and the positive contribution of hmgA disruption to the actinorhodin biosynthesis in Streptomyces coelicolor.
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhang
authors.forename: Linqi
authors.initials: L
authors.lastname: Wang
authors.forename: Shuli
authors.initials: S
authors.lastname: Zhang
authors.forename: Haihua
authors.initials: H
authors.lastname: Yang
authors.forename: Huarong
authors.initials: H
authors.lastname: Tan
mesh_terms: D000880:Anthraquinones / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D024003:HMGA Proteins / Q000378:metabolism*; D050560:Homogentisate 1,2-Dioxygenase / Q000378:metabolism; D006867:Hydrolases / Q000502:physiology*; D014158:Transcription, Genetic / Q000502:physiology*; D015533:Transcriptional Activation; D014443:Tyrosine / Q000378:metabolism; D000095622:Benzoisochromanequinones
chemical_list: D000880:Anthraquinones; D024003:HMGA Proteins; D050560:Homogentisate 1,2-Dioxygenase; D006867:Hydrolases; D014443:Tyrosine; C062907:2,6-dioxo-6-phenylhexa-3-enoate hydrolase; C013390:actinorhodin; D000095622:Benzoisochromanequinones