Disease relevance of ilvE

• The nucleotide sequence preceding and including the beginning of the ilvE gene of the ilvGEDA operon of Escherichia coli K12 [1].
• Expression from the phage of the ilvE and lacZ genes is controlled by an intact ilv control region also carried by this phage [2].
• A branched-chain aminotransferase gene (ilvE) from Lactococcus lactis LM0230 was identified on a 9-kb chromosomal insert by complementation in Escherichia coli DL39 [3].
• Deoxyribonucleic acid (DNA) from a lambda phage carrying an ilvC-lac fusion was employed as a template for the in vitro synthesis of beta-galactosidase under the control of the ilvC promoter [4].
• Amino acid sequence of Salmonella typhimurium branched-chain amino acid aminotransferase [5].

High impact information on ilvE

• Evidence that this promoter coupling is DNA supercoiling-dependent is provided by the observation that a novobiocin-induced decrease in global negative superhelicity results in an increase in ilvY promoter activity and a decrease in ilvC promoter activity predicted by the in vitro data [6].
• It does, however, cause a conformational change of the IlvY protein-DNA complex, which is correlated with the partial relief of an IlvY protein-induced bend of the DNA helix in the ilvC promoter region [7].
• In this report, we use topoisomer sets of defined superhelical densities as DNA templates in a purified in vitro transcription system to demonstrate transcriptional coupling between the divergently transcribed ilvY and ilvC promoters of the ilvYC operon of Escherichia coli [8].
• Most significantly, this work establishes the contribution of the internal promoter (ilvEp, located downstream of the polar site) to the expression of the downstream genes in E. coli K12 wild-type and mutant strains (ilvG) and by extension to the role of this promoter in S. typhimurium [9].
• Transcriptional polarity enhances the contribution of the internal promoter, ilvEp, in the expression of the ilvGMEDA operon in wild-type Escherichia coli K12 [9].

Chemical compound and disease context of ilvE

• In Escherichia coli K-12, two enzymes, encoded by ilvE and tyrB, catalyze the amination of 2-ketoisocaproate (2-KIC) to form leucine [10].
• Genetic mapping experiments have established that two recently isolated valine-resistant mutants of the K-12 strain of Escherichia coli have lesions lying between ilvE and rbs [11].
• Structures of Escherichia coli branched-chain amino acid aminotransferase and its complexes with 4-methylvalerate and 2-methylleucine: induced fit and substrate recognition of the enzyme [12].
• The labeled glutamate in turn serves as an amine donor to an appropriate alpha-keto acid using the Escherichia coli branched-chain amino acid aminotransferase, the subcloning and overexpression of which is described [13].
• The branched-chain amino acid aminotransferase of Escherichia coli was crystallized in two crystal systems, monoclinic and tetragonal, from polyethylene glycol and ammonium sulfate solutions, pH 7.0, respectively [14].

Biological context of ilvE

• It was previously determined that the distal portion of the ilvGMEDA operon was expressed despite the insertion of transposons into ilvG and ilvE [15].
• The DNA sequence of the 570 base pairs that precedes and includes the beginning of the ilvE gene shows no evidence of a leader-attenuator region [1].
• Estimates of the transcriptional role of the internal promoter on ilvE gene expression during growth conditions in excess and limiting branch chain amino acids is presented [16].
• The replication origin is located approximately 30 kb from the ilvE gene and 20 kb from the rrnC 16S rRNA cistron [17].
• ilvE gene of Escherichia coli was inserted into the region downstream of the tac promotor [18].

Associations of ilvE with chemical compounds

• In addition, other ilvE leu double mutants were found to be unable to grow on 2-KIC in place of leucine [10].
• The ilvE gene product alone can reverse a phenylalanine requirement [19].
• In extracts of an ilvE- tyrB- aspC- triple mutant, no aminotransferase activity for the alpha-keto acids of tyrosine, phenylalanine, or aspartate could be detected [19].
• Crystal structures of branched-chain amino acid aminotransferase complexed with glutamate and glutarate: true reaction intermediate and double substrate recognition of the enzyme [20].
• Branched-chain amino acid aminotransferase (BCAT), which has pyridoxal 5'-phosphate as a cofactor, is a key enzyme in the biosynthetic pathway of hydrophobic amino acids (leucine, isoleucine, and valine) [20].

Other interactions of ilvE

• The ilvGMEDA operon of Escherichia coli K-12 contains an internal promoter, PE, in the distal portion of the ilvM gene immediately upstream from the ilvE gene [16].
• It was concluded that the genes ilvE, ilvD and ilvA constitute a single operon and are transcribed from E to A [21].

Analytical, diagnostic and therapeutic context of ilvE

• Crystallization and preliminary X-ray characterization of branched-chain amino acid aminotransferase from Escherichia coli [14].

References