School of Biology, University Park, University of Nottingham, Nottingham NG7 2RD, UK.
Fungal Genet Biol. 2010 Aug;47(8):683-92. doi: 10.1016/j.fgb.2010.04.011. Epub 2010 May 7.
The ability to resist anti-microbial compounds is of key evolutionary benefit to microorganisms. Aspergillus niger has previously been shown to require the activity of a phenylacrylic acid decarboxylase (encoded by padA1) for the decarboxylation of the weak-acid preservative sorbic acid (2,4-hexadienoic acid) to 1,3-pentadiene. It is now shown that this decarboxylation process also requires the activity of a putative 4-hydroxybenzoic acid (3-octaprenyl-4-hydroxybenzoic acid) decarboxylase, encoded by a gene termed ohbA1, and a putative transcription factor, sorbic acid decarboxylase regulator, encoded by sdrA. The padA1,ohbA1 and sdrA genes are in close proximity to each other on chromosome 6 in the A. niger genome and further bioinformatic analysis revealed conserved synteny at this locus in several Aspergillus species and other ascomycete fungi indicating clustering of metabolic function. This cluster is absent from the genomes of A. fumigatus and A. clavatus and, as a consequence, neither species is capable of decarboxylating sorbic acid.
微生物具有抵抗抗菌化合物的能力，这对其进化具有重要意义。先前已经证实，黑曲霉（Aspergillus niger）需要苯丙烯酸脱羧酶（由 padA1 编码）的活性，才能将弱酸性防腐剂山梨酸（2,4-己二烯酸）脱羧为 1,3-戊二烯。现在表明，这个脱羧过程还需要一个假定的 4-羟基苯甲酸（3-辛基-4-羟基苯甲酸）脱羧酶的活性，该酶由一个称为 ohbA1 的基因编码，以及一个假定的转录因子，山梨酸脱羧酶调节剂，由 sdrA 编码。在黑曲霉基因组的第 6 号染色体上，padA1、ohbA1 和 sdrA 基因彼此靠近，进一步的生物信息学分析表明，在几个曲霉属物种和其他子囊菌真菌中，该基因座存在保守的同线性，表明代谢功能的聚类。这种聚类不存在于烟曲霉（A. fumigatus）和构巢曲霉（A. clavatus）的基因组中，因此，这两个物种都不能脱羧山梨酸。
