Disease relevance of cysE

• This gene organization is also conserved in Bacillus stearothermophilus where the cysE and cysS genes show high amino acid identity with those of B. subtilis [1].
• New cysE-pyrE-linked rfa mutation in Escherichia coli K-12 that results in a heptoseless lipopolysaccharide [2].
• Isolation and characterization of a lambda transducing bacteriophage carrying the cysE gene of Escherichia coli K-12 [3].
• In vivo and in vitro processing of the Bacillus subtilis transcript coding for glutamyl-tRNA synthetase, serine acetyltransferase, and cysteinyl-tRNA synthetase [4].
• A cysE gene encoding a serine acetyltransferase (SAT) potentially involved in the biosynthesis of cysteine was identified approximately 4 kb upstream of the previously described aapJQMP gene cluster that encodes an amino acid permease in Rhizobium leguminosarum strain 3841 [5].

High impact information on cysE

• O-acetylation of serine, the committed step of the pathway, was released from feedback inhibition by mutating the serine acetyltransferase gene [6].
• T. vaginalis appears to lack serine acetyltransferase, the source of O-acetylserine in many cells, but has a functional 3-phosphoglycerate dehydrogenase and an O-phosphoserine aminotransferase that together result in the production of O-phosphoserine, suggesting that this is the physiological substrate [7].
• Serine acetyltransferase (SAT) catalyzes the first step of cysteine synthesis in microorganisms and higher plants [8].
• We also cloned and characterized cDNA encoding serine acetyltransferase (SAT), a key enzyme in the sulfate assimilatory cysteine biosynthetic pathway [9].
• We cloned and characterized cDNAs that encode the regulated enzyme serine acetyltransferase (SAT) in this pathway from these amoebae by genetic complementation of a cysteine-auxotrophic Escherichia coli strain with the amoebic cDNA libraries [10].

Chemical compound and disease context of cysE

• While transformants of E. coli UQ818 with archaeal and bacterial cysS genes grew at a nonpermissive temperature, growth was also supported by elevated intracellular cysteine levels, e.g., by transformation with an E. coli cysE allele (encoding serine acetyltransferase) or by the addition of cysteine to the culture medium [11].
• cysB and cysE mutants of Escherichia coli K12 show increased resistance to novobiocin [12].
• Isolation of Nicotiana plumbaginifolia cDNAs encoding isoforms of serine acetyltransferase and O-acetylserine (thiol) lyase in a yeast two-hybrid system with Escherichia coli cysE and cysK genes as baits [13].
• PCR random mutagenesis into Escherichia coli serine acetyltransferase: isolation of the mutant enzymes that cause overproduction of L-cysteine and L-cystine due to the desensitization to feedback inhibition [14].
• We previously found a marked production of L-cysteine from glucose in recombinant Escherichia coli cells expressing an altered cysE gene encoding feedback inhibition-insensitive serine acetyltransferase [15].

Biological context of cysE

• A T-box sequence and a rho-independent terminator known to regulate expression of other aminoacyl-tRNA synthetase genes and of some amino acid biosynthetic operons in Bacillus sp., were found between gltX and cysE [1].
• Protein products of the cysE region at 81 min on the chromosome of Escherichia coli K-12 (1) were analyzed by the maxicell method [16].
• The cysE gene contained an open reading frame consisting of 819 bp, equivalent to a protein of 273 amino acids [17].
• To analyse the structural basis for this mutation the cysE genes both from wild-type E. coli and the mutant strain were cloned and their nucleotide sequences determined [17].
• We applied the yeast two-hybrid system for screening of a cDNA library of Nicotiana plumbaginifolia for clones encoding plant proteins interacting with two proteins of Escherichia coli: serine acetyltransferase (SAT, the product of cysE gene) and O-acetylserine (thiol)lyase A, also termed cysteine synthase (OASTL-A, the product of cysK gene) [13].

Associations of cysE with chemical compounds

• The addition of O-acetyl-L-serine to the cysE strain produced a 5.5-fold increase in the rate of synthesis of cys mRNA [18].
• This unusual relationship was also observed among spontaneous novobiocin resistant (Novr) mutants: 10% of Novr mutants isolated on rich (LA) plates with novobiocin could not grow on minimal plates, and among those approximately half were cysB or cysE mutants [12].
• In contrast, the growth of an DeltayrhA mutant or a luxS mutant, inactivated for the S-ribosyl-homocysteinase step of the S-adenosylmethionine recycling pathway, was strongly reduced with methionine, whereas a DeltayrhA DeltacysK or cysE mutant did not grow at all under the same conditions [19].
• In the double mutant cysE cysB2971, the cysteine biosynthetic enzymes are absent with the exception of O-acetyl-L-serine sulphydrylase [20].
• The cDNA clone Sat-1 conferred serine acetyltransferase activity (with apparent Km for the two substrates acetyl CoA and L-serine of 0.043 and 3.47 mmol/dm3 respectively) on the cysE mutant [21].

Regulatory relationships of cysE

• When a tnaA-disrupted E. coli strain expressing the altered cysE gene was transformed with a plasmid carrying the bcr gene, the transformant exhibited more L-cysteine production than cells carrying the vector only [15].

Other interactions of cysE

• The locus, mutM, mapped near the cysE locus, which is at 81 min on the genetic map [22].
• These results show that the cysE-like gene located upstream from iscS is not essential for cell growth and that the cysE-like gene and the iscSUA-hscBA-fdx genes are contained within separate transcription units [23].

Analytical, diagnostic and therapeutic context of cysE

• Restriction mapping and functional analysis of cloned DNA allowed us to localize the rfaR1 locus and to orient it with respect to the neighbouring cysE chromosomal marker [24].
• PCR random mutagenesis in the cysE gene encoding Escherichia coli serine acetyltransferase was employed to isolate the mutant enzymes that, due to a much less feedback inhibition by L-cysteine, cause overproduction of L-cysteine and L-cystine in the recombinant strains [14].
• Cysteine synthase from Escherichia coli is a bienzyme complex comprised of serine acetyltransferase (SAT) and O-acetylserine sulfhydrylase A. The site of interaction of a SAT molecule was investigated by gel chromatography and surface plasmon technique using various mutant-type SATs, to better understand the mechanism involved in complex formation [25].
• Molecular cloning and characterization of a plant serine acetyltransferase playing a regulatory role in cysteine biosynthesis from watermelon [26].
• Accumulation of both SATase and beta-PA/CSase in soluble extracts of E. coli was confirmed by immunoblotting [27].

References