Open AccessA yeast system for expression of human cystathionine beta-synthase: structural and functional conservation of the human and yeast genes.
Author(s) -
Warren D. Kruger,
David Cox
Publication year - 1994
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.91.14.6614
Subject(s) - yeast , cystathionine beta synthase , biology , gene , genetics , complementary dna , saccharomyces cerevisiae , gene expression , structural gene , enzyme , conserved sequence , biochemistry , microbiology and biotechnology , cysteine , peptide sequence , escherichia coli
Human cystathionine beta-synthase (CBS; EC 4.2.1.22) deficiency results in a recessive genetic disorder whose clinical and biochemical manifestations vary greatly among affected individuals. In an effort to identify and analyze mutations in the human CBS gene, we have developed a yeast expression system for human CBS. We have cloned and sequenced a human cDNA that codes for CBS and have expressed the human CBS protein in yeast cells lacking endogenous CBS. The human enzyme produced in yeast is functional both in vitro and in vivo. We have also cloned and sequenced the yeast gene, CYS4, that codes for CBS. The predicted human and yeast CBS proteins are 38% identical and 72% similar to each other, as well as sharing significant similarity with bacterial cysteine synthase. These results demonstrate the evolutionary conservation of CBS and establish the utility of a yeast expression system for studying human CBS.