Elucidation of expression/regulation of genes involved in microbial polyhydroxylalkanoate (PHA)

阐明微生物聚羟基链烷酸酯 (PHA) 相关基因的表达/调控

• 批准号: 11217207
• 负责人: YAMANE Tsuneo
• 金额: $ 28.48万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research on Priority Areas
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11217207/
• 关键词: PHA; PHB; methylotroph; microbial denitrifyer; Paracoccus denitrificans; phaA; phaR; PHA depolymerase; P(3HB); P(3HV); phaP; PHB depolymerase; pha C; pha P; pha R

With aim of elucidating regulation mechanism of PHA synthesis/degradation within denitrifyer and methylotroph, Paracoccus denitrificans, studies were carried out on genes/enzymes/metabolism levels, and the following have been achieved.1. A gene named phaR, was discovered downstream of phaP that encoded PHA granule-associated protein, phasin. PhaR was a transcription factor which bound promoter region of phaP and also bound the PHA granule. It regulated the size of PHA granule.2. Genes involved in PHA synthesis/degradation, i.e phaA, phaB, phaC, and phaZ, were expressed almost constitutively irrespective of PHA synthesis level.A metabolite, Coenzyme A, was proposed as a global regulator of PHA biosynthesis.3. Three enzymes involved in the intracellular degradation of PHA, i.e. two different kinds of PHA depolymerases, and PHB oligomer hydrolase, were purified and their biochemical characteristics were elucidated. One of the PHA depolymerases was a novel enzyme which yielded 3-hydroxylbutyrate monomer directly from PHB polymer.

为了阐明嗜热菌和甲基营养菌Paracoccus ficans合成/降解PHA的调控机制，本论文从基因/酶/代谢水平进行了研究，主要研究内容如下：1.在phaP的下游发现了一个名为phaR的基因，该基因编码PHA颗粒相关蛋白，相蛋白。PhaR是一个转录因子，它与phaP的启动子区结合，也与PHA颗粒结合。调节PHA颗粒大小. PHA合成/降解相关基因phaA、phaB、phaC和phaZ的表达与PHA合成水平无关，代谢产物辅酶A被认为是PHA生物合成的全局调节因子.对三种参与PHA胞内降解的酶，即两种不同类型的PHA解聚酶和PHB寡聚物水解酶进行了纯化，并阐明了它们的生化特性。其中一种PHA解聚酶是一种新的酶，它可以直接从聚羟基丁酸酯聚合物中产生3-羟基丁酸酯单体。

项目成果

Akira Maehara et al.: "Analyses of a Polyhydroxyalkanoic Acid Granule-Associated 16-Kilodalton Protein and Its Putative Regulator in the pha Locus of Paracoccus denitrificans"Journal of Bacteriology. 181・9. 2914-2921 (1999)

Akira Maehara 等人：“脱氮副球菌 pha 基因座中聚羟基链烷酸颗粒相关 16-Kilodalton 蛋白及其推定调节因子的分析”细菌学杂志 181·9（1999）。

T.Yamane, S.Ueda, and A. Maehara, ed. by Yoshio Inoue: "Synthesis of Biodegradable Plastics by Microorganisms, Recent Technology of Green Plastics"CMC.Co. Ltd.. Chap.6(71-83) (2002)

T.Yamane、S.Ueda 和 A. Maehara，编辑。

Dai Gao et al.: "Identification of the intracellular polyhydroxyalkanoate depolymerase gene of Paracoccus denitrificans and some properties of the gene product"FEMS Microbiology Letters. 196. 159-164 (2001)

戴高等：“脱氮副球菌胞内聚羟基脂肪酸酯解聚酶基因的鉴定及该基因产物的一些特性”FEMS微生物学快报。

Y.Takagi et al: "Biosyntesis of polyhydroxyalkanoate with a thiophenoxy side group obtained from Pseudomonas putida"Macromolecules. 32. 8315-8318 (1999)

Y.Takagi 等人：“从恶臭假单胞菌获得的具有噻吩氧基侧基的聚羟基链烷酸酯的生物合成”大分子。

S.Ueda et al: "Purification and properties of d- (-) -3 -hydroxybutyrate oligomer hydrolase of Paracoccus denitrificans"FEMS Microbiology Letters. 206. 179-184 (2002)

S.Ueda 等人：“脱氮副球菌的 d-(-)-3-羟基丁酸酯寡聚物水解酶的纯化和特性”FEMS 微生物学快报。