The metG gene of Aspergillus nidulans encoding cystathionine beta-lyase: cloning and analysis

Curr Genet. 1999 Jul;35(6):638-46. doi: 10.1007/s002940050463.


The metG gene of Aspergillus nidulans encoding cystathionine beta-lyase, an enzyme of the main pathway of methionine synthesis, was cloned by complementation of a metG mutation. A comparison of metG genomic DNA and a cDNA copy derived from different A. nidulans strains revealed a marked DNA sequence polymorphism manifested mostly by silent point mutations. cDNA of the A. nidulans metG gene complemented the Escherichia coli metC69 mutation impairing cystathionine beta-lyase. This gene contains two introns and codes for a protein of 439 amino acids. The protein shows homology with bacterial, yeast and plant cystathionine beta-lyases, as well as with other enzymes belonging to a large family of pyridoxal 5'-phosphate binding proteins. Transcription of the metG gene is not appreciably regulated by the concentration of sulphur source in the growth medium.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Aspergillus nidulans / chemistry
  • Aspergillus nidulans / enzymology
  • Aspergillus nidulans / genetics*
  • Base Sequence
  • Cloning, Molecular
  • DNA, Complementary / chemistry
  • DNA, Complementary / genetics
  • DNA, Complementary / isolation & purification
  • DNA, Fungal / chemistry
  • DNA, Fungal / genetics
  • DNA, Fungal / isolation & purification
  • Gene Expression Regulation, Enzymologic
  • Gene Expression Regulation, Fungal
  • Genes, Fungal / genetics*
  • Lyases / genetics*
  • Molecular Sequence Data
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid


  • DNA, Complementary
  • DNA, Fungal
  • Lyases
  • cystathionine beta-lyase

Associated data

  • GENBANK/U28383