Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.6.1.19 (GABA transaminase)
 808 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Alanine-glyoxylate aminotransferase (AGT) 2 is a pyridoxal 5'-phosphate dependent, mitochondrial enzyme which, in the rat, is expressed at a high level in the kidney. The amino acid sequences of nine tryptic and seven CNBr peptides of the rat kidney AGT2 were determined. Three overlapping cDNAs encoding the AGT2 were cloned on the basis of its partial amino acid sequences by means of a polymerase chain reaction-based approach involving rat kidney poly(A)+ RNA. The complete cDNA sequence comprised 1,919 bases, and contained a 1,536-base open reading frame which encodes a polypeptide of 512 amino acid residues with a putative presequence consisting of 39 amino acid residues at the amino terminus, giving a precursor protein with a molecular mass of 57,150 Da. The sequence of AGT2 exhibits significant homology with neither peroxisomal AGT1 from human liver nor mitochondrial AGT1 from rat liver. However, the sequence of AGT2 exhibited 30.8, 29.2, and 27.1% identity with those of Escherichia coli 4-aminobutyrate aminotransferase, rat ornithine aminotransferase, and Pseudomonas cepacia 2,2-dialkylglycine decarboxylase, respectively. The active site sequences were also well conserved among these aminotransferases. AGT2, thus, is more similar to the other aminotransferases than to AGT1. The results suggest that the rat kidney AGT2 may play a biological role in amino acid metabolism distinct from that of AGT1.
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PMID:Molecular cloning and sequencing of a cDNA encoding alanine-glyoxylate aminotransferase 2 from rat kidney. 759 50

4-Aminobutyrate aminotransferase, which catalyzes the conversion of 4-aminobutyrate to succinic semialdehyde, is a key enzyme of the 4-aminobutyrate shunt. The amino acid sequence predicted from the cDNA sequence shows that the precursor protein consists of the mature enzyme of 473 amino acid residues and an amino-terminal segment of 27 amino acids (Kwon, O. S., Park, J., and Churchich, J. E. (1992) J. Biol. Chem. 267, 7215-7216). A recombinant 4-aminobutyrate aminotransferase has been expressed in Escherichia coli using pETIId as expression vector. The protein has been purified and characterized as a dimer (2 x 55 kDa). NH2-terminal sequence analysis has revealed the presence of an extra amino-terminal segment (signal peptide) predicted from the cDNA sequence. The isolated precursor of 4-aminobutyrate aminotransferase contains pyridoxal 5-phosphate and exhibits catalytic activity (18 units/mg) comparable to that of the mature enzyme (20 units/mg). The presequence peptide of the precursor of mitochondrial 4-aminobutyrate aminotransferase does not interfere with the folding and functional properties of the mature moiety of the aminotransferase.
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PMID:Isolation and characterization of recombinant mitochondrial 4-aminobutyrate aminotransferase. 838 14