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Cystathionine γ‐lyase of Saccharomyces cerevisiae : Structural gene and cystathionine γ‐synthase activity
Author(s) -
Ono BunIchiro,
Ishii Nobuya,
Naito Kazuhide,
Miyoshi ShinIchi,
Shinoda Sumio,
Yamamoto Sumiyo,
Ohmori Shinji
Publication year - 1993
Publication title -
yeast
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.923
H-Index - 102
eISSN - 1097-0061
pISSN - 0749-503X
DOI - 10.1002/yea.320090409
Subject(s) - cystathionine beta synthase , antiserum , saccharomyces cerevisiae , biology , biochemistry , escherichia coli , lyase , polyacrylamide gel electrophoresis , microbiology and biotechnology , structural gene , enzyme , peptide sequence , gel electrophoresis , strain (injury) , cystathionine gamma lyase , gene , genetics , cysteine , antibody , anatomy
Purification of Saccharomyces cerevisiae cystathionine γ‐lyase (γ‐CTLase) was hampered by the presence of a protein migrating very close to it in various types of column chromatography. The enzyme and the contaminant were nevertheless separated by polyacrylamide gel electrophoresis. N‐terminal amino acid sequence analysis indicated that they are coded for by CYS3 ( CYI1 ) and MET17 ( MET25 ), respectively, leading to the conclusion that CYS3 is the structural gene for γ‐CTLase and that the contaminant is O ‐acetylserine/ O ‐acetylhomoserine sulfhydrylase (OAS/OAH SHLase). Based on these findings, we purified γ‐CTLase by the following strategy: (1) extraction of OAS/OAH SHLase from a CYS3 ‐disrupted strain; (2) preparation of antiserum against it; (3) identification of a strain devoid of the OAS/OAH SHLase protein using this antiserum; and (4) extraction of γ‐CTLase from this strain. Purified γ‐CTLase had cystathionine γ‐synthase (γ‐CTSase) activity if O ‐succinylhomoserine, but not O ‐acetylhomoserine, was used as substrate. From this notion we discuss the evolutional relationship between S. cerevisiae γ‐CTLase and Escherichia coli γ‐CTSase.