Isolation and analysis of xlnR, encoding a transcriptional activator co-ordinating xylanolytic expression in Aspergillus niger

Mol Microbiol. 1998 Jan;27(1):131-42. doi: 10.1046/j.1365-2958.1998.00666.x.


Complementation by transformation of an Aspergillus niger mutant lacking xylanolytic activity led to the isolation of the xlnR gene. The xlnR gene encodes a polypeptide of 875 amino acids capable of forming a zinc binuclear cluster domain with similarity to the zinc clusters of the GAL4 superfamily of transcription factors. The XlnR-binding site 5'-GGCTAAA-3' was deduced after electrophoretic mobility shift assays, DNase I footprinting and comparison of various xylanolytic promoters. The importance of the second G within the presumed XlnR binding site 5'-GGCTAAA-3' was confirmed in vitro and in vivo. The 5'-GGCTAAA-3' consensus sequence is found within several xylanolytic promoters of various Aspergillus species and Penicillium chrysogenum. Therefore, this sequence may be an important and conserved cis-acting element in induction of xylanolytic genes in filamentous fungi. Our results indicate that XlnR is a transcriptional activator of the xylanolytic system in A. niger.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Aspergillus niger / enzymology
  • Aspergillus niger / genetics*
  • Aspergillus niger / metabolism*
  • Base Sequence
  • Binding, Competitive
  • Blotting, Northern
  • Blotting, Southern
  • Blotting, Western
  • DNA Footprinting
  • DNA, Fungal / chemistry
  • Deoxyribonuclease I
  • Electrophoresis, Polyacrylamide Gel
  • Fungal Proteins*
  • Gene Expression Regulation, Enzymologic / physiology
  • Gene Expression Regulation, Fungal / physiology*
  • Molecular Sequence Data
  • Mutation
  • Promoter Regions, Genetic / genetics
  • Restriction Mapping
  • Sequence Analysis, DNA
  • Trans-Activators / genetics
  • Transcription, Genetic
  • Transformation, Genetic
  • Xylan Endo-1,3-beta-Xylosidase
  • Xylans / metabolism*
  • Xylosidases / chemistry
  • Xylosidases / genetics*
  • Xylosidases / metabolism
  • Zinc Fingers / genetics
  • Zinc Fingers / physiology


  • DNA, Fungal
  • Fungal Proteins
  • Trans-Activators
  • XlnR protein, Aspergillus
  • Xylans
  • Deoxyribonuclease I
  • Xylosidases
  • Xylan Endo-1,3-beta-Xylosidase

Associated data

  • GENBANK/AJ001909