Physical localization of yeast CYS3, a gene whose product resembles the rat gamma-cystathionase and Escherichia coli cystathionine gamma-synthase enzymes.
We have cloned, sequenced and physically mapped the CYS3 gene of Saccharomyces cerevisiae. This gene can complement the cys3-1 allele, and disruptions at this locus lead to cysteine auxotrophy. The predicted CYS3 product is closely related (46% identical) to the rat cystathionine gamma-lyase (Erickson et al., 1990), but differs in lacking cysteine residues. These results provide further evidence that the S288C strain of yeast resembles mammals in synthesizing cysteine solely via a trans-sulfuration pathway. The CYS3 product was found to have strong homology to three other enzymes involved in cysteine metabolism: the Escherichia coli metB and metC products and the S. cerevisiae MET25 gene product. The trans-sulfuration enzymes appear to form a diverged family and carry out related functions from bacteria to mammals.
Biology Department, McGill University, Montreal, Canada.
A B
AB
Barton
D B
DB
Kaback
M W
MW
Clark
T
T
Keng
B F
BF
Ouellette
R K
RK
Storms
B
B
Zeng
W
W
Zhong
N
N
Fortin
S
S
Delaney
D000595:Amino Acid Sequence; D000818:Animals; D019757:Carbon-Oxygen Lyases; D002874:Chromosome Mapping; D015825:Chromosomes, Fungal; D003001:Cloning, Molecular; D003542:Cystathionine gamma-Lyase / Q000235:genetics*; D003545:Cysteine / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D005800:Genes, Fungal / Q000235:genetics*; D008190:Lyases / Q000235:genetics; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D051381:Rats; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
C022696:O-succinylhomoserine (thiol)-lyase; D008190:Lyases; D019757:Carbon-Oxygen Lyases; D003542:Cystathionine gamma-Lyase; D003545:Cysteine