title: Both a PKS and a PPTase are involved in melanin biosynthesis and regulation of Aureobasidium melanogenum XJ5-1 isolated from the Taklimakan desert.
abstract: A PKS1 gene responsible for the melanin biosynthesis and a NPG1 gene in Aureobasidium melanogenum XJ5-1 were cloned and characterized. An ORF of the PKS1 gene encoding a protein with 2165 amino acids contained 6495bp while an ORF of the NPG1 gene encoding a protein with 340 amino acids had 1076bp. After analysis of their promoters, it was found that expression of both the PKS1 gene and the NPG1 gene was repressed by nitrogen sources and glucose, respectively. The PKS deduced from the cloned gene consisted of one ketosynthase, one acyl transferase, two acyl carrier proteins, one thioesterase and one cyclase while the PPTase belonged to the family Sfp-type. After disruption of the PKS1 gene and the NPG1 gene, expression of the PKS1 gene and the NPG1 gene and the melanin biosynthesis in the disruptants K5 and DP107 disappeared and expression of the PKS1 gene in the disruptant DP107 was also negatively influenced. However, after the NPG1 gene was complemented in the disruptant DP107, the melanin biosynthesis in the complementary strain BP17 was restored and expression of the PKS1 gene and the NPG1 gene was greatly enhanced, suggesting that the PKS was indeed activated and regulated by the PPTase and expression of the PKS1 gene and the NPG1 gene had a coordinate regulation.
authors.affiliation: College of Marine Life Sciences, Ocean University of China, Yushan Road, No. 5, Qingdao, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Jiang
authors.affiliation: College of Marine Life Sciences, Ocean University of China, Yushan Road, No. 5, Qingdao, China.
authors.forename: Guang-Lei
authors.initials: GL
authors.lastname: Liu
authors.affiliation: College of Marine Life Sciences, Ocean University of China, Yushan Road, No. 5, Qingdao, China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Chi
authors.affiliation: Key Laboratory of Protection and Utilization of Biological Resource in Tarim Basin, Tarim University, Xinjiang, China.
authors.forename: Jian-Ming
authors.initials: JM
authors.lastname: Wang
authors.affiliation: Key Laboratory of Protection and Utilization of Biological Resource in Tarim Basin, Tarim University, Xinjiang, China.
authors.forename: Ly-Ly
authors.initials: LL
authors.lastname: Zhang
authors.affiliation: College of Marine Life Sciences, Ocean University of China, Yushan Road, No. 5, Qingdao, China. Electronic address: zhenming@sdu.edu.cn.
authors.forename: Zhen-Ming
authors.initials: ZM
authors.lastname: Chi
mesh_terms: D001203:Ascomycota / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D002681:China; D003889:Desert Climate; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D055786:Gene Knockout Techniques; D005800:Genes, Fungal; D005816:Genetic Complementation Test; D008543:Melanins / Q000096:biosynthesis* / Q000235:genetics*; D010802:Phylogeny; D048630:Polyketide Synthases / Q000235:genetics* / Q000378:metabolism*; D017855:Transferases (Other Substituted Phosphate Groups) / Q000235:genetics* / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D005656:Fungal Proteins; D008543:Melanins; C082662:phosphopantetheinyl transferase; D048630:Polyketide Synthases; D017855:Transferases (Other Substituted Phosphate Groups)
keywords: A. melanogenum; Coordinate regulation; Melanin biosynthesis; PKS; PPTase; The Taklimakan desert