The role of cotA gene in proton extrusion of Synechocystis PCC6803

cotA基因在集胞藻PCC6803质子挤出中的作用

• 批准号: 09640767
• 负责人: OGAWA Teruo
• 金额: $ 1.92万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09640767/
• 关键词: cyanobacteria; proton extrusion; Synechocystis; Synechococcus; pxcA; cotA; cytoplasmic membrane; cemA; らん藻; プロトン輸送; cotA-pxcA; 変異株; CO_2取り込み; NO_3^-取り込み

Light-induced proton extrusion has been observed with various strains of cyanobacteria. We found that pxcA (formerly named as cotA) complemented a Synechocystis mutant unable to grow at acidic pH and that inactivation of this gene abolished the activity of light-induced proton extrusion. PxcA genes of Synechocystis PCC6803 and Synechococcus PCC7942 encode proteins of 440 and 427 amino acids, respectively, that showed significant sequence homology to a protein in the inner envelope membrane of chloroplasts encoded by cemA in chloroplast genome. We have demonstrated that PxcA is localized in the cytoplasmic membrane. The pxcA-inactivated mutant was unable to grow at acidic pHs or at low Na^+ concentrations. The activities of CO_2 uptake and NO_3 uptake by the mutant were inhibited under these conditions. There are two types of CemA/PxcA.CemA in chloroplasts of higher plants consists of 229 - 231 amino acids whereas CemA/PxcA in liverwort, Chlamydomonas and cyanobacteria are much larger and consist of 421-500 amino acids. Both short and long types of CemA/PxcA contain 4 membrane spanning domains. Phylogenetic tree for PxcA of cyanobacteria and CemA of plants and Chlamydomonas suggested that PxcA and CemA have the same ancestor.

光诱导的质子挤出已被观察到与各种菌株的蓝藻。我们发现，pxcA（以前命名为科塔）补充集胞藻突变体无法在酸性pH值下生长，该基因的失活废除光诱导的质子挤出的活动。集胞藻PCC 6803和集胞藻PCC 7942的PxcA基因分别编码440和427个氨基酸的蛋白质，与叶绿体基因组中cemA编码的叶绿体内被膜蛋白具有显著的序列同源性。我们已经证明，PxcA是本地化的细胞质膜。pxcA失活的突变体不能在酸性pH或低Na^+浓度下生长。在此条件下，突变体吸收CO_2和NO_3的活性受到抑制。CemA/PxcA有两种类型，高等植物叶绿体中的CemA由229 - 231个氨基酸组成，而苔类、衣原体和蓝藻中的CemA/PxcA大得多，由421-500个氨基酸组成。短型和长型CemA/PxcA均含有4个跨膜结构域。通过对蓝藻PxcA和植物CemA的系统发育树分析，推测它们具有相同的祖先。

项目成果

Sonoda,M.,Katoh,H.,Katoh,A.,Ohkawa,H.,Vermaas,W.,Ogawa,T.: "Structure and function of cemA homologue (pxcA) in cyanobacteria." The Chloroplast: From Molecular Biology to Biotechnology (ed.Akuyunoglou),. 印刷中. (1999)

Sonoda, M.、Katoh, H.、Katoh, A.、Ohkawa, H.、Vermaas, W.、Okawa, T.：“蓝藻中 cemA 同源物 (pxcA) 的结构和功能：来自分子生物学。”生物技术（Akuyunoglou 编），出版中（1999 年）。

Sonoda, M., H.Katoh, W.Vermaas, G.Schmetterer and T.Ogawa.: "Photosynthetic Electron Transport Involved in the PxcA-Dependent Proton Extrusion in Synechocystis sp.PCC6803 : Effect of pxcA Inactivation on CO_2, HCO_3-and NO_3-Uptake." Journal of Bacteriolo

Sonoda, M., H.Katoh, W.Vermaas, G.Schmetterer 和 T.Okawa.：“集胞藻 PCC6803 中 PxcA 依赖性质子挤出涉及的光合电子传输：pxcA 失活对 CO_2、HCO_3-和

"Structure and function of cemA homologue (pxcA) in cyanobacteria." The Chloroplast : Form mole-cular Biology to Biotechnology (ed.Akuyunoglou). (in press.).

“蓝藻中 cemA 同源物 (pxcA) 的结构和功能。”

Sonoda,M.,K.Kitano,A.Katoh,H.Katoh,H.Ohkawa,T.Ogawa: "Size of cotA and identification of the gene product in Synechoystis sp.strain PCC 6803." Journal of Bacteriology. 179. 3845-3850 (1997)

Sonoda,M.,K.Kitano,A.Katoh,H.Katoh,H.Ohkawa,T.Okawa：“集胞藻菌株 PCC 6803 中 cotA 的大小和基因产物的鉴定。”

Ogawa,T.: "Molecular mechanisms of CO_2 concentration and proton extrusion in cyanobacteria" Stress Responses of Photosynthetic Organisms(eds.K.Satoh & N.Murata)Elsevier,Amsterdam. 181-196 (1998)

小川，T.：“蓝藻中CO_2浓度和质子挤出的分子机制”光合生物的应激反应（eds.K.Satoh）