Dohmoto M, Tsunoda H, Isaji G, Chiba R, Yamaguchi K
Institute for Gene Research, Kanazawa University, Japan.
DNA Res. 2000 Oct 31;7(5):283-9. doi: 10.1093/dnares/7.5.283.
Nitrilase (nitrile aminohydrolase, EC 3.5.5.1) catalyzes the hydrolysis of indole-3-acetonitrile (IAN) to indole-3-acetic acid (IAA). Arabidopsis thaliana genome has four nitrilase genes (NIT1, NIT2, NIT3 and NIT4). Three (NIT1, NIT2 and NIT3) of the four genes have high similarity. We have cloned two NIT4 homologs (TNIT4A and TNIT4B) from tobacco (Nicotiana tabacum). Genomic Southern hybridization, among other experiments, strongly suggests that tobacco has NIT4 homologs but not NIT1 to NIT3 homologs. Introduction of Arabidopsis NIT2 into tobacco conferred IAN-mediated growth inhibition, probably due to hydrolysis of IAN to IAA, while ectopic expression of TNIT4A had little effect on the sensitivity of transgenic plants to IAN. Nitrilase activity of TNIT4 proteins is discussed.
腈水解酶（腈氨基水解酶，EC 3.5.5.1）催化吲哚-3-乙腈（IAN）水解生成吲哚-3-乙酸（IAA）。拟南芥基因组有四个腈水解酶基因（NIT1、NIT2、NIT3和NIT4）。这四个基因中的三个（NIT1、NIT2和NIT3）具有高度相似性。我们从烟草（烟草）中克隆了两个NIT4同源基因（TNIT4A和TNIT4B）。除其他实验外，基因组Southern杂交强烈表明烟草有NIT4同源基因，但没有NIT1至NIT3同源基因。将拟南芥NIT2导入烟草会导致IAN介导的生长抑制，这可能是由于IAN水解为IAA，而TNIT4A的异位表达对转基因植物对IAN的敏感性影响很小。文中讨论了TNIT4蛋白的腈水解酶活性。
