Kobayashi M, Shinohara M, Sakoh C, Kataoka M, Shimizu S
Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
Proc Natl Acad Sci U S A. 1998 Oct 27;95(22):12787-92. doi: 10.1073/pnas.95.22.12787.
A lactonohydrolase from Fusarium oxysporum AKU 3702 is an enzyme catalyzing the hydrolysis of aldonate lactones to the corresponding aldonic acids. The amino acid sequences of the NH2 terminus and internal peptide fragments of the enzyme were determined to prepare synthetic oligonucleotides as primers for the PCR. An approximate 1, 000-base genomic DNA fragment thus amplified was used as the probe to clone both genomic DNA and cDNA for the enzyme. The lactonohydrolase genomic gene consists of six exons separated by five short introns. A novel type of RNA editing, in which lactonohydrolase mRNA included the insertion of guanosine and cytidine residues, was observed. The predicted amino acid sequence of the cloned lactonohydrolase cDNA showed significant similarity to those of the gluconolactonase from Zymomonas mobilis, and paraoxonases from human and rabbit, forming a unique superfamily consisting of C-O cleaving enzymes and P-O cleaving enzymes. Lactonohydrolase was expressed under the control of the lac promoter in Escherichia coli.
尖孢镰刀菌AKU 3702的内酯水解酶是一种催化醛糖酸内酯水解为相应醛糖酸的酶。测定了该酶氨基末端和内部肽段的氨基酸序列，以制备合成寡核苷酸作为PCR引物。由此扩增得到的约1000个碱基的基因组DNA片段用作探针，用于克隆该酶的基因组DNA和cDNA。内酯水解酶基因组基因由6个外显子组成，中间间隔5个短内含子。观察到一种新型的RNA编辑，即内酯水解酶mRNA包含鸟苷和胞苷残基的插入。克隆的内酯水解酶cDNA的预测氨基酸序列与运动发酵单胞菌的葡萄糖酸内酯酶以及人和兔的对氧磷酶的氨基酸序列具有显著相似性，形成了一个由C-O裂解酶和P-O裂解酶组成的独特超家族。内酯水解酶在大肠杆菌的lac启动子控制下表达。
