Linked Life Data

10806361

Source:http://linkedlifedata.com/resource/pubmed/id/10806361

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2000-7-6
pubmed:databankReference
pubmed:abstractText
The biosynthesis of aflatoxins (B(1), G(1), B(2), and G(2)) is a multi-enzyme process controlled genetically by over 20 genes. In this study, we report the identification and characterization of the avfA gene, which was found to be involved in the conversion of averufin (AVF) to versiconal hemiacetal acetate (VHA), in Aspergillus parasiticus and A. flavus; a copy of avfA gene was also cloned from a non-aflatoxin producing strain A. sojae. Complementation of an averufin-accumulating, non-aflatoxigenic mutant strain of A. parasiticus, SRRC 165, with the avfA gene cloned from A. flavus, restored the ability of the mutant to convert AVF to VHA and to produce aflatoxins B(1), G(1), B(2), and G(2). Sequence analysis revealed that a single amino acid replacement from aspartic acid to asparagine disabled the function of the enzyme in the mutant strain SRRC 165. The A. parasiticus avfA was identified to be a homolog of previously sequenced, but functionally unassigned transcript, stcO, in A. nidulans based on sequence homology at both nucleotide (57%) and amino acid (55%) levels. In addition to avfA, another aflatoxin pathway gene, omtB, encoding for an O-methyltransferase involved in the conversion of demethylsterigmatocystin (DMST) to sterigmatocystin (ST) and dihydrodemethylsterigmatocystin (DHDMST) to dihydrosterigmatocystin (DHST), was cloned from A. parasiticus, A. flavus, and A. sojae. The omtB gene was found to be highly homologous to stcP from A. nidulans, which has been reported earlier to be involved in a similar enzymatic step for the sterigmatocystin formation in that species. RT-PCR data demonstrated that both the avfA and avfA1 as well as omtB genes in A. parasiticus were expressed only in the aflatoxin-conducive medium. An analysis of the degrees of homology for the two reported genes between the Aspergillus species A. parasiticus, A. flavus, A. nidulans and A. sojae was conducted.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0378-1119
pubmed:author
pubmed:issnType
Print
pubmed:day
2
pubmed:volume
248
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
157-67
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:10806361-Aflatoxins, pubmed-meshheading:10806361-Amino Acid Sequence, pubmed-meshheading:10806361-Anthraquinones, pubmed-meshheading:10806361-Aspergillus, pubmed-meshheading:10806361-Aspergillus nidulans, pubmed-meshheading:10806361-Base Sequence, pubmed-meshheading:10806361-Cloning, Molecular, pubmed-meshheading:10806361-DNA, Fungal, pubmed-meshheading:10806361-Fungal Proteins, pubmed-meshheading:10806361-Gene Expression Regulation, Enzymologic, pubmed-meshheading:10806361-Gene Expression Regulation, Fungal, pubmed-meshheading:10806361-Methyltransferases, pubmed-meshheading:10806361-Molecular Sequence Data, pubmed-meshheading:10806361-Oxidoreductases, pubmed-meshheading:10806361-Point Mutation, pubmed-meshheading:10806361-Sequence Alignment, pubmed-meshheading:10806361-Sequence Analysis, DNA, pubmed-meshheading:10806361-Sequence Homology, Amino Acid, pubmed-meshheading:10806361-Sequence Homology, Nucleic Acid
pubmed:year
2000
pubmed:articleTitle
Cloning and characterization of avfA and omtB genes involved in aflatoxin biosynthesis in three Aspergillus species.
pubmed:affiliation
Southern Regional Research Center, USDA, Agricultural Research Service, New Orleans, LA 70179, USA. jiuyu@commserver.srrc.usda.gov
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't