Kwon O S, Park J, Churchich J E
Department of Biochemistry, University of Tennessee, Knoxville 37916.
J Biol Chem. 1992 Apr 15;267(11):7215-6.
4-Aminobutyrate aminotransferase is a key enzyme of the 4-aminobutyric acid shunt. It is responsible for the conversion of the neurotransmitter 4-aminobutyrate to succinic semialdehyde. By using oligonucleotide probes based on partial amino acid sequence data for the pig brain enzyme, several overlapping cDNA clones of 2.0-2.2 kilobases in length have been isolated. The largest cDNA clone was selected for sequence analysis. The amino acid sequence predicted from the cDNA sequence shows that the precursor of 4-aminobutyrate aminotransferase consists of the mature enzyme of 473 amino acid residues and an amino-terminal segment of 27 amino acids attributed to the signal peptide. The cofactor pyridoxal-5-P is bound to lysine residue 330 of the deduced amino acid sequence of the mature enzyme.
4-氨基丁酸转氨酶是4-氨基丁酸分流途径的关键酶。它负责将神经递质4-氨基丁酸转化为琥珀酸半醛。通过使用基于猪脑酶部分氨基酸序列数据的寡核苷酸探针，已分离出几个长度为2.0 - 2.2千碱基的重叠cDNA克隆。选择最大的cDNA克隆进行序列分析。从cDNA序列预测的氨基酸序列表明，4-氨基丁酸转氨酶的前体由473个氨基酸残基的成熟酶和归因于信号肽的27个氨基酸的氨基末端片段组成。辅因子磷酸吡哆醛与成熟酶推导氨基酸序列的赖氨酸残基330结合。
