A Consensus Ochratoxin A Biosynthetic Pathway: Insights from the Genome Sequence of Aspergillus ochraceus and a Comparative Genomic Analysis

被引:7
作者
Wang, Yan [1 ,3 ]
Wang, Liuqing [1 ]
Wu, Fan [2 ]
Liu, Fei [1 ]
Wang, Qi [1 ]
Zhang, Xiaoling [2 ]
Selvaraj, Jonathan Nimal [1 ]
Zhao, Yueju [1 ,3 ]
Xing, Fuguo [1 ,3 ]
Yin, Wen-Bing [2 ]
Liu, Yang [1 ,3 ]
机构
[1] Chinese Acad Agr Sci, Inst Food Sci & Technol, Beijing, Peoples R China
[2] Chinese Acad Sci, Inst Microbiol, State Key Lab Mycol, Beijing, Peoples R China
[3] Minist Agr, Key Lab Agroprod Qual & Safety Control Storage &, Beijing, Peoples R China
基金
美国国家科学基金会;
关键词
ochratoxin A; biosynthetic pathway; Aspergillus ochraceus; genome; comparative genomics; regulation; mycotoxin; PENICILLIUM-NORDICUM; GENE PREDICTION; A BIOSYNTHESIS; IDENTIFICATION; ANNOTATION; SELECTION; ALIGNMENT; STRAINS; CLUSTER; CLONING;
D O I
10.1128/AEM.01009-18
中图分类号
Q81 [生物工程学(生物技术)]; Q93 [微生物学];
学科分类号
071005 ; 0836 ; 090102 ; 100705 ;
摘要
Ochratoxin A (OTA) is a toxic secondary metabolite produced by Aspergillus and Penicillium species that widely contaminates food and feed. We sequenced and assembled the complete similar to 37-Mb genome of Aspergillus ochraceus fc-1, a well-known producer of OTA. Key genes of the OTA biosynthetic pathway were identified by comparative genomic analyses with five other sequenced OTA-producing fungi: A. carbonarius, A. niger, A. steynii, A. westerdijkiae, and Penicillium nordicum. OTA production was completely inhibited in the deletion mutants (Delta otaA, Delta otaB, Delta otaC, Delta otaD, and Delta otaR1), and OTA biosynthesis was restored by feeding a postblock substrate to the corresponding mutant. The OTA biosynthetic pathway was unblocked in the Delta otaD mutant by the addition of heterologously expressed halogenase. OTA biosynthesis begins with a polyketide synthase (PKS), OtaA, utilizing acetyl coenzyme A (acetyl-CoA) and malonyl-CoA to synthesize 7-methylmellein, which is oxidized to OT beta by cytochrome P450 monooxygenase (OtaC). OT beta and L-beta-phenylalanine are combined by a nonribosomal peptide synthetase (NRPS), OtaB, to form an amide bond to synthesize OTB. Finally, OTB is chlorinated by a halogenase (OtaD) to OTA. The otaABCD genes were expressed at low levels in the Delta otaR1 mutant. A second regulator, otaR2, which is adjacent to the biosynthetic gene, could modulate only the expression of otaA, otaB, and otaD. Thus, we have identified a consensus OTA biosynthetic pathway that can be used to prevent and control OTA synthesis and will help us understand the variation and production of the intermediate components in the biosynthetic pathway. IMPORTANCE Ochratoxin A (OTA) is a significant mycotoxin that contaminates cereal products, coffee, grapes, wine, cheese, and meat. OTA is nephrotoxic, carcinogenic, teratogenic, and immunotoxic. OTA contamination is a serious threat to food safety, endangers human health, and can cause huge economic losses. At present, >20 species of the genera Aspergillus and Penicillium are known to produce OTA. Here we demonstrate that a consensus OTA biosynthetic pathway exists in all OTA-producing fungi and is encoded by a gene cluster containing four highly conserved biosynthetic genes and a bZIP transcription factor.
引用
收藏
页数:15
相关论文
共 56 条
[1]   Aspergillus westerdijkiae polyketide synthase gene "aoks1" is involved in the biosynthesis of ochratoxin A [J].
Bacha, Nafees ;
Atoui, Ali ;
Mathieu, Florence ;
Liboz, Thierry ;
Lebrihi, Ahmed .
FUNGAL GENETICS AND BIOLOGY, 2009, 46 (01) :77-84
[2]   GeneWise and genomewise [J].
Birney, E ;
Clamp, M ;
Durbin, R .
GENOME RESEARCH, 2004, 14 (05) :988-995
[3]   Selection of conserved blocks from multiple alignments for their use in phylogenetic analysis [J].
Castresana, J .
MOLECULAR BIOLOGY AND EVOLUTION, 2000, 17 (04) :540-552
[4]   The Aspergillus parasiticus protein AFLJ interacts with the aflatoxin pathway-specific regulator AFLR [J].
Chang, PK .
MOLECULAR GENETICS AND GENOMICS, 2003, 268 (06) :711-719
[5]  
Collyda C, 2007, STUD HEALTH TECHNOL, V129, P1245
[6]   ProtTest 3: fast selection of best-fit models of protein evolution [J].
Darriba, Diego ;
Taboada, Guillermo L. ;
Doallo, Ramon ;
Posada, David .
BIOINFORMATICS, 2011, 27 (08) :1164-1165
[7]   Analysis of differentially-expressed ochratoxin A biosynthesis genes of Penicillium nordicum [J].
Färber, P ;
Geisen, R .
EUROPEAN JOURNAL OF PLANT PATHOLOGY, 2004, 110 (5-6) :661-669
[8]   Sequence-specific binding by Aspergillus nidulans AflR, a C6 zinc cluster protein regulating mycotoxin biosynthesis [J].
Fernandes, M ;
Keller, NP ;
Adams, TH .
MOLECULAR MICROBIOLOGY, 1998, 28 (06) :1355-1365
[9]   Identification of a Halogenase Involved in the Biosynthesis of Ochratoxin A in Aspergillus carbonarius [J].
Ferrara, Massimo ;
Perrone, Giancarlo ;
Gambacorta, Lucia ;
Epifani, Filomena ;
Solfrizzo, Michele ;
Gallo, Antonia .
APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 2016, 82 (18) :5631-5641
[10]  
Frisvad JC, 2004, STUD MYCOL, P23