Disease relevance of metC

• In the enteric bacteria Escherichia coli and Salmonella enterica, these reactions are catalyzed by irreversible cystathionine-gamma-synthase and cystathionine-beta-lyase enzymes [1].
• The temperature-sensitive Escherichia coli mutant ecfts metC (Lieberman and Hong, 1974), previously shown to be defective in the coupling of metabolic energy to active transport, is also altered in a wide variety of cellular activities at the nonpermissive temperature [2].
• Properties of the Corynebacterium glutamicum metC gene encoding cystathionine beta-lyase [3].
• Regulation of the metC-cysK operon, involved in sulfur metabolism in Lactococcus lactis [4].
• Isolation of the patC gene encoding the cystathionine beta-lyase of Lactobacillus delbrueckii subsp. bulgaricus and molecular analysis of inter-strain variability in enzyme biosynthesis [5].

High impact information on metC

• While the enzyme showed high gamma-lyase activity toward L-cystathionine (Km = 0.5 mM, Vmax = 2.5 units/mg) with an optimum pH of 8.2, no residual cystathionine beta-lyase behavior and only marginal reactivity toward L-cystine and L-cysteine were detected [6].
• Aminoethoxyvinylglycine showed slow and tight binding characteristics with a Ki of 10.5 microM, comparable with its effect on cystathionine beta-lyase [6].
• The region upstream of the beta-cystathionase (metC) gene in B. avium 197 lacked regulatory sequences ("Met boxes") described for metC in enteric species, and enzyme production was not repressed by methionine [7].
• The three-dimensional structure of cystathionine beta-lyase from Arabidopsis was determined by Patterson search techniques, using the structure of tobacco (Nicotiana tabacum) cystathionine gamma-synthase as starting point [8].
• The three-dimensional structure of cystathionine beta-lyase from Arabidopsis and its substrate specificity [8].

Chemical compound and disease context of metC

• Overexpression of CBL complemented the methionine auxotrophy of an E. coli metC mutant, demonstrating in vivo that this enzyme functions as a CBL [5].
• In analogy to CysB from Escherichia coli, we propose that CmbR requires acetylserine to be able to bind the activation sites and subsequently activate transcription of the metC-cysK operon [4].
• Accumulation of L-cystathionine by an Escherichia coli mutant deficient in cystathionine beta-lyase [9].

Biological context of metC

• The chloramphenicol resistance determinant of a plasmid integrated at the ISP-I locus was mapped by PBS1 transduction and was found to be closely linked to metC (99.5%) [10].
• Also, the overexpression of plasmid-encoded metC did not affect mal gene expression, nor did the deduced amino acid sequence of MetC show homology to that of MalY [11].
• The encoded CmbR protein is homologous to the LysR family of regulator proteins and is an activator of the metC-cysK operon [4].
• Other sulfur sources tested showed no significant effect on metC-cysK gene expression [4].
• These mutations were mapped to a locus designated ctaA, located at 127 degrees between pyrD and metC on the B. subtilis chromosome [12].

Anatomical context of metC

• The metC gene, which is known to code for a cystathione-beta-lyase, was cloned from the axilla isolate Corynebacterium striatum Ax20 and heterologously expressed in E. coli [13].

Associations of metC with chemical compounds

• In addition we found that O-acetyl-l-serine, the substrate of cysteine synthase, was an inducer of the metC-cysK operon [4].
• The structure of the catalytic dimer and mode of PLP binding in Tnase resemble those found in aspartate amino-transferase, TPL, omega-amino acid pyruvate aminotransferase, dialkylglycine decarboxylase (DGD), cystathionine beta-lyase and ornithine decarboxylase [14].
• Cystathionine beta-lyase (CBL) is a member of the gamma-family of pyridoxal-5'-phosphate (PLP)-dependent enzymes (Alexander et al., 1994) that cleave C(beta,gamma)-S bonds of a broad variety of substrates [15].

Analytical, diagnostic and therapeutic context of metC

• Cloning, purification, and crystallization of Escherichia coli cystathionine beta-lyase [16].
• A SDS-PAGE analysis identified a putative cystathionine beta-lyase band with approximate Mr of 41,000 that consisted of 368 amino acids encoded from ORF1 [3].

References