This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Liang, S. H. Articles by Linz, J. E. Search for Related Content PubMed PubMed Citation Articles by Liang, S. H. Articles by Linz, J. E. Agricola Articles by Liang, S. H. Articles by Linz, J. E.

 Previous Article  |  Next Article 

Appl. Environ. Microbiol., 12 1996, 4568-4575, Vol 62, No. 12
Copyright © 1996, American Society for Microbiology

Characterization of the function of the ver-1A and ver-1B genes, involved in aflatoxin biosynthesis in Aspergillus parasiticus

SH Liang, CD Skory and JE Linz
Department of Food Science and Human Nutrition, Michigan State University, East Lansing 48824, USA.

The ver-1A gene was cloned and its nucleotide sequence was determined as part of a previous study on aflatoxin B1 (AFB1) biosynthesis in the filamentous fungus Aspergillus parasiticus SU-1. A second copy of this gene, ver-1B, was tentatively identified in this fungal strain. In this study, ver-1B was cloned by screening an A. parasiticus cosmid library with a ver-1A probe. The nucleotide sequence of ver-1B was determined. The predicted amino acid sequence of ver-1B had 95% identity with ver- 1A. A translational stop codon, found in the ver-1B gene coding region, indicated that it encodes a truncated polypeptide. To confirm the function of the ver-1 genes in AFB1 synthesis, a plasmid (pDV-VA) was designed to disrupt ver-1A and/or ver-1B by transformation of the AFB1 producer A. parasiticus NR-1. One disruptant, VAD-102, which accumulated the pathway intermediate versicolorin A was obtained. Southern hybridization analysis of VAD-102 revealed that ver-1A but not ver-1B was disrupted. A functional ver-1A gene was transformed back into strain VAD-102. Transformants which received ver-1A produced AFB1, confirming that ver-1A is the only functional ver-1 gene in A. parasiticus SU-1 and that its gene product is involved in the conversion of versicolorin A to sterigmatocystin in AFB1 biosynthesis. A duplicated chromosomal region (approximately 12 kb) was identified upstream from ver-1A and ver-1B by Southern hybridization analysis. This duplicated region contained the aflR gene, which is proposed to be one regulator of AFB1, synthesis. A similar gene duplication was also identified in several other strains of A. parasiticus.

This article has been cited by other articles:

• Cary, J. W., Ehrlich, K. C., Bland, J. M., Montalbano, B. G. (2006). The Aflatoxin Biosynthesis Cluster Gene, aflX, Encodes an Oxidoreductase Involved in Conversion of Versicolorin A to Demethylsterigmatocystin. Appl. Environ. Microbiol. 72: 1096-1101 [Abstract] [Full Text]  
• Ehrlich, K. C., Montalbano, B., Boue, S. M., Bhatnagar, D. (2005). An Aflatoxin Biosynthesis Cluster Gene Encodes a Novel Oxidase Required for Conversion of Versicolorin A to Sterigmatocystin. Appl. Environ. Microbiol. 71: 8963-8965 [Abstract] [Full Text]  
• Sakuno, E., Wen, Y., Hatabayashi, H., Arai, H., Aoki, C., Yabe, K., Nakajima, H. (2005). Aspergillus parasiticus Cyclase Catalyzes Two Dehydration Steps in Aflatoxin Biosynthesis. Appl. Environ. Microbiol. 71: 2999-3006 [Abstract] [Full Text]  
• Calvo, A. M., Bok, J., Brooks, W., Keller, N. P. (2004). veA Is Required for Toxin and Sclerotial Production in Aspergillus parasiticus. Appl. Environ. Microbiol. 70: 4733-4739 [Abstract] [Full Text]  
• Roze, L. V., Miller, M. J., Rarick, M., Mahanti, N., Linz, J. E. (2004). A Novel cAMP-response Element, CRE1, Modulates Expression of nor-1 in Aspergillus parasiticus. J. Biol. Chem. 279: 27428-27439 [Abstract] [Full Text]  
• Yu, J., Chang, P.-K., Ehrlich, K. C., Cary, J. W., Bhatnagar, D., Cleveland, T. E., Payne, G. A., Linz, J. E., Woloshuk, C. P., Bennett, J. W. (2004). Clustered Pathway Genes in Aflatoxin Biosynthesis. Appl. Environ. Microbiol. 70: 1253-1262 [Full Text]  
• Lee, L.-W., Chiou, C.-H., Linz, J. E. (2002). Function of Native OmtA In Vivo and Expression and Distribution of This Protein in Colonies of Aspergillus parasiticus. Appl. Environ. Microbiol. 68: 5718-5727 [Abstract] [Full Text]  
• Takahashi, T., Chang, P.-K., Matsushima, K., Yu, J., Abe, K., Bhatnagar, D., Cleveland, T. E., Koyama, Y. (2002). Nonfunctionality of Aspergillus sojae aflR in a Strain of Aspergillus parasiticus with a Disrupted aflR Gene. Appl. Environ. Microbiol. 68: 3737-3743 [Abstract] [Full Text]  
• Bradshaw, R. E., Bhatnagar, D., Ganley, R. J., Gillman, C. J., Monahan, B. J., Seconi, J. M. (2002). Dothistroma pini, a Forest Pathogen, Contains Homologs of Aflatoxin Biosynthetic Pathway Genes. Appl. Environ. Microbiol. 68: 2885-2892 [Abstract] [Full Text]  
• Chang, P.-K., Yu, J., Ehrlich, K. C., Boue, S. M., Montalbano, B. G., Bhatnagar, D., Cleveland, T. E. (2000). adhA in Aspergillus parasiticus Is Involved in Conversion of 5'-Hydroxyaverantin to Averufin. Appl. Environ. Microbiol. 66: 4715-4719 [Abstract] [Full Text]