Mayorga M E, Timberlake W E
Department of Genetics, University of Georgia, Athens 30602.
Mol Gen Genet. 1992 Nov;235(2-3):205-12. doi: 10.1007/BF00279362.
The Aspergillus nidulans wA gene is required for synthesis of a green pigment present in the walls of mature asexual spores (conidia); wA mutants produce colorless (white) conidia. We determined the transcriptional structure and DNA sequence of the wA gene. wA consists of 5 exons separated by short (40-60 bp) introns. The processed transcript has the potential to encode a protein consisting of 1986 amino acid residues. The predicted WA polypeptide showed extensive sequence similarities with bacterial and fungal polyketide synthases and vertebrate fatty acid synthases, particularly within conserved active sites. Properties of the yellow conidial wall pigment intermediate suggest that it is a polyketide rather than a fatty acid. It is therefore likely that wA encodes all or part of a polyketide synthase involved in the formation of this pigment intermediate.
构巢曲霉的wA基因是成熟无性孢子（分生孢子）壁中存在的绿色色素合成所必需的；wA突变体产生无色（白色）分生孢子。我们确定了wA基因的转录结构和DNA序列。wA由5个外显子组成，被短（40 - 60 bp）内含子隔开。加工后的转录本有可能编码一种由1986个氨基酸残基组成的蛋白质。预测的WA多肽与细菌和真菌的聚酮合酶以及脊椎动物的脂肪酸合酶显示出广泛的序列相似性，特别是在保守的活性位点内。黄色分生孢子壁色素中间体的特性表明它是一种聚酮化合物而非脂肪酸。因此，wA可能编码参与这种色素中间体形成的聚酮合酶的全部或部分。
