Regulation of the feruloyl esterase (faeA) gene from Aspergillus niger.
Feruloyl esterases can remove aromatic residues (e.g., ferulic acid) from plant cell wall polysaccharides (xylan, pectin) and are essential for complete degradation of these polysaccharides. Expression of the feruloyl esterase-encoding gene (faeA) from Aspergillus niger depends on D-xylose (expression is mediated by XlnR, the xylanolytic transcriptional activator) and on a second system that responds to aromatic compounds with a defined ring structure, such as ferulic acid and vanillic acid. Several compounds were tested, and all of the inducing compounds contained a benzene ring which had a methoxy group at C-3 and a hydroxy group at C-4 but was not substituted at C-5. Various aliphatic groups occurred at C-1. faeA expression in the presence of xylose or ferulic acid was repressed by glucose. faeA expression in the presence of ferulic acid and xylose was greater than faeA expression in the presence of either compound alone. The various inducing systems allow A. niger to produce feruloyl esterase not only during growth on xylan but also during growth on other ferulic acid-containing cell wall polysaccharides, such as pectin.
de Vries
R P
RP
Molecular Genetics of Industrial Micro-organisms, Wageningen Agricultural University, NL-6703 HA Wageningen, The Netherlands.
Visser
J
J
D001234:Aspergillus niger / Q000201:enzymology* / Q000235:genetics*; D002265:Carboxylic Ester Hydrolases / Q000096:biosynthesis / Q000235:genetics*; D004790:Enzyme Induction; D004794:Enzyme Repression; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects / Q000528:radiation effects; D016296:Mutagenesis; D009153:Mutagens / Q000494:pharmacology; D011401:Promoter Regions, Genetic; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D014466:Ultraviolet Rays
D005656:Fungal Proteins; D009153:Mutagens; D012097:Repressor Proteins; D015534:Trans-Activators; C115443:XlnR protein, Aspergillus; C071237:CreA protein, Aspergillus nidulans; D002265:Carboxylic Ester Hydrolases; C070196:feruloyl esterase