Analysis of the genes for porphyrin biosynthetic pathway in higher plants utilizing the light-sensitive mutants of Escherichia coli

1)利用此cDNA互补大肠杆菌突变体的胸腺嘧啶营养缺陷的能力，分离了水稻（Oryza sativa L.indica）胸苷酸合成酶（TS）的cDNA克隆。[Kanjo & Inokuchi，Plant Physiol.（Gene Register），120，634（1999）]2）通过针对BT3 δ hemG：：Km^R细胞的不良生长的功能互补分离大豆（Glycine max）的原卟啉原IX氧化酶的cDNA克隆。核苷酸序列分析表明，插入的cDNA长度为1745 bp。它包括一个单一的开放阅读框架，编码由502个氨基酸残基组成的蛋白质。推导的大豆PPOX的氨基酸序列与烟草线粒体PPOX的氨基酸序列同源性为67%。它在N-末端共享一些推测为线粒体易位信号的氨基酸残基。[Kanjo等人，Plant Physiol.（Gene Register），121，1384（1999）]3）我们研究了氧化酶的可能替代途径， ...更多信息 通过分离和研究大肠杆菌突变体，使原卟啉原IX转化为原卟啉IX，当hemG基因被破坏时，这些突变体仍能正常生长。这表明大肠杆菌需氧粪卟啉原氧化酶具有不仅氧化粪卟啉原III而且氧化原卟啉原IX的内在能力。[Narita等人，摩尔Gen.（Genet.，261，1012-1020（1999）]4）黄瓜（Cucumis sativus）亚铁螯合酶cDNA（hemH）的推定成熟区在大肠杆菌中过表达，纯化至均一并检测其酶性质。用抗体对酶的免疫定位表明，亚铁螯合酶在黄瓜下胚轴和根中均有表达，但在子叶中几乎不表达。[Suzuki等人，植物细胞生理学，41，192-199（2000）]5）首次克隆了菠菜（Spinacia oleracea）质体PPOX cDNA，并对纯化的成熟质体PPOX的N-末端序列进行了分析，探讨了质体PPOX向叶绿体转运的机制。[Che例如，植物生理学，124，59-70（2000）]

1) By taking advantage of the ability of such a cDNA to complement the thymine auxotrophy of a mutant of Escherichia coli, a cDNA clone for thymidylate synthase (TS) of rice (Oryza sativa L.indica) was isolated. [Kanjo ＆ Inokuchi, Plant Physiol. (Gene Register), 120, 634 (1999)]2) A cDNA clone for protoporphyrinogen IX oxidase of soybean (Glycine max was isolated by functional complementation against the poor growth of BT3 delta hemG : : Km^R cells. Nucleotide sequence analysis of the cDNA insert revealed that the insert was 1745 bp in length. It included a single open reading frame that encoded a protein consisting of 502 amino acid residues. The deduced amino acid sequence of PPOX from soybean was 67 % homologous to that of mitochondrial PPOX from tobacco. It shares some amino acid residues at the N-terminus speculated to be a mitochondrial translocation signal. [Kanjo et al., Plant Physiol. (Gene Register), 121, 1384 (1999)]3) We examined poessible alternate pathways for the oxidati … More on of protoporphyrinogen IX to protoporphyrin IX, by isolating and investigating E.coli mutants that can still grow normally when the hemG gene is disrupted. It was suggested that the E.coli aerobic coproporphyrinogen oxidase has an intrinsic capacity to oxidize not only coproporphyrinogen III but also protoporhyrinogen IX.[Narita et al., Mol. Gen. (Genet., 261, 1012-1020 (1999)]4) A putative mature region of a cucumber (Cucumis sativus) ferrochelatase cDNA (hemH) was overexpressed in E.coli, purified to homogenity and examined its enzymatic properties. Immunolocalization of the enzyme examined with antibody demonstrated that the ferrochelatase was present in both hypocotyls and roots but hardly in cotyledons of cucumber. [Suzuki et al., Plant Cell Physiol., 41, 192-199 (2000)]5) We reported the first cloning of spinach (Spinacia oleracea) plastidal PPOX cDNA and analysis of the N-terminal sequence in mature plastidal PPOX purified from spinach chloroplast and discussed the mechanism of the transport of plastidal PPOX into chloroplasts. [Che et al., Plant Physiol., 124, 59-70 (2000)] Less