Cloning and characterization of the Aspergillus nidulans cysB gene encoding cysteine synthase.
The cysB gene of A. nidulans was cloned by complementation of a cysB mutation. This is the first cloned eukaryotic genomic sequence coding for cysteine synthase. The gene contains one 71-bp intron and codes for a protein of 370 amino acids. Its N-terminal region has characteristic features of transit peptides, suggesting mitochondrial localisation of the enzyme. The protein shows homology with bacterial and plant cysteine synthases among which it occupies a remote phylogenetic position and apparently represents a distinct subfamily. Transcription of the cysB gene is not appreciably regulated by the concentration of methionine in the growth medium.
Topczewski
J
J
Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106 Warsaw, Poland.
Sienko
M
M
Paszewski
A
A
D000595:Amino Acid Sequence; D000603:Amino Acids, Sulfur / Q000235:genetics / Q000378:metabolism; D001233:Aspergillus nidulans / Q000235:genetics* / Q000378:metabolism*; D001483:Base Sequence; D003001:Cloning, Molecular; D003547:Cysteine Synthase / Q000235:genetics* / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics; D008928:Mitochondria / Q000737:chemistry / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D000603:Amino Acids, Sulfur; D018076:DNA, Complementary; D012333:RNA, Messenger; D003547:Cysteine Synthase