Disease relevance of CYS3

• Cystathionine gamma-lyase of Streptomyces phaeochromogenes. The occurrence of cystathionine gamma-lyase in filamentous bacteria and its purification and characterization [1].
• Cystathionine gamma-lyase (EC 4.4.1.1) is widely distributed in actinomycetes, e.g. genera Streptomyces, Micromonospora, Micropolyspora, Mycobacterium, Nocardia, Streptosporangium, and Streptoverticillium [1].
• We therefore conclude that S. cerevisiae cystathionine gamma-lyase and E. coli cystathionine gamma-synthase are homologous in both structure and in vitro function and propose that their different in vivo functions are due to the unavailability of O-succinylhomoserine in S. cerevisiae and the scarceness of cystathionine in E. coli [2].

High impact information on CYS3

• The nucleotide mapping of DNA double-strand breaks at the CYS3 initiation site of meiotic recombination in Saccharomyces cerevisiae [3].
• To uncover the regulatory mechanisms active in DSB formation, we have monitored the change in local chromatin structure at the ARG4 and CYS3 recombination hot spots over the course of meiosis [4].
• Two of the last three newly identified Mac1 target genes have no known function; the third, YFR055w, is homologous to cystathionine gamma-lyase encoded by CYS3 [5].
• In the MSH2 PMS1 background, strains heteroallelic for frameshift mutations in CYS3 exhibit a frequency of gene conversion greater than that observed for either marker alone [6].
• The study of the meiotic progeny of diploid strains heterozygous at the STR1 locus has shown that the str1-1 mutation undergoes a particularly high frequency of meiotic gene conversion [7].

Biological context of CYS3

• Genetic analysis indicates that CYS3 is a hotspot of meiotic gene conversion, with a putative 5'-3' polarity gradient of conversion frequencies [6].
• By comparison of the deduced amino acid sequence with the N-terminal amino acid sequence of cystathionine gamma-lyase, CYS3 (CYI1) was concluded to be the structural gene for this enzyme [2].
• Yeast cys3 and gsh1 mutant cells display overlapping but non-identical symptoms of oxidative stress with regard to subcellular protein localization and CDP-DAG metabolism [8].
• The amino-acid substitutions of the CYS3 protein present in a temperature-sensitive cys-3 mutant and in a second-site revertant of a cys-3 null mutation are presented and are shown to affect their DNA-binding activities [9].
• Surprisingly, an extended promoter region of the cys-3 gene in the Mauriceville strain and in N. intermedia was very well conserved with that of the standard N. crassa gene, including the presence of three CYS3-binding sites possibly involved in autogenous control [9].

Associations of CYS3 with chemical compounds

• The introduction of genes from Sac. cerevisiae constituting the cystathionine pathway (CYS4 and CYS3) into Sch. pombe Deltamet26 cells restored growth in the absence of adenine [10].
• The only phenotypic consequence of the inactivation of STR1 or STR4 is cysteine auxotrophy [11].
• Using a Saccharomyces cerevisiae strain having the activities of serine O-acetyl-transferase (SATase), O-acetylserine/O-acetylhomoserine sulphydrylase (OAS/OAH SHLase), cystathionine beta-synthase (beta-CTSase) and cystathionine gamma-lyase (gamma-CTLase), we individually disrupted CYS3(coding for gamma-CTLase) and CYS4 (coding for beta-CTSase) [12].
• An amino-terminal serine/threonine-rich domain of CYS3 alone strongly activated expression of beta-galactosidase, the yeast reporter [9].
• Alternatively, yeast and some bacteria assimilate sulfur into homocysteine, which serves as a sulfhydryl group donor in the synthesis of cysteine by reverse transsulfurylation with a cystathionine-beta-synthase and cystathionine-gamma-lyase [13].

Other interactions of CYS3

• Expression of various hybrid GAL4-CYS3 fusion proteins in yeast was used to detect regions involved in gene activation [9].
• 2. The protein showed a number of cystathionine-related activities, i.e., cystathionine beta-lyase (EC 4.4.1.8), cystathionine gamma-lyase, and cystathionine gamma-synthase (EC 4.2.99.9) with L-homoserine as substrate [14].
• The effectors governing the biosynthesis of cysteine synthase and gamma-cystathionase seemed different from those playing a role in gamma-GT regulation and it was only under conditions of total sulphate deprivation that all these enzymes were derepressed [15].
• Cystathionine gamma-lyase of Saccharomyces cerevisiae was immobilized to aminohexyl-Sepharose through the cofactor pyridoxal 5'-phosphate and was characterized with respect to its cystathionine gamma-synthase activity [16].

Analytical, diagnostic and therapeutic context of CYS3

• Immobilization of Saccharomyces cerevisiae cystathionine gamma-lyase and application of the product to cystathionine synthesis [16].

References