Phenazine-1-carboxylate

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 二氮杂萘
• 英文名称: Phenazine-1-carboxylate
• 化学式: C13H7N2O2-
• 分子量: 223.21
• InChiKey: JGCSKOVQDXEQHI-UHFFFAOYSA-M

计算性质

• 辛醇/水分配系数(LogP)：
  2.8
• 重原子数：
  17
• 可旋转键数：
  0
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.0
• 拓扑面积：
  65.9
• 氢给体数：
  0
• 氢受体数：
  4

反应信息

• 作为反应物：
  描述：

  Phenazine-1-carboxylate 、 S-腺苷蛋氨酸 生成 5-Methylphenazine-1-carboxylate 、 S-(5'-腺苷)-L-高半胱氨酸
  参考文献：
  名称：

  Structural and Functional Analysis of the Pyocyanin Biosynthetic Protein PhzM from Pseudomonas aeruginosa^,

  摘要：

  Pyocyanin is a biologically active phenazine produced by the human pathogen Pseudomonas aeruginosa. It is thought to endow P. aeruginosa with a competitive growth advantage in colonized tissue and is also thought to be a virulence factor in diseases such as cystic fibrosis and AIDS where patients are commonly infected by pathogenic Pseudomonads due to their immunocompromised state. Pyocyanin is also a chemically interesting compound due to its unusual oxidation-reduction activity. Phenazine-1-carboxylic acid, the precursor to the bioactive phenazines, is synthesized from chorismic acid by enzymes encoded in a seven-gene cistron in P. aeruginosa and in other Pseudomonads. Phenzine-1-carboxylic acid is believed to be converted to pyocyanin by the sequential actions of the putative S-adenosylmethionine-dependent N-methyltransferase PhzM and the putative flavin-dependent hydroxylase PhzS. Here we report the 1.8 A crystal structure of PhzM determined by single anomalous dispersion. Unlike many methyltransferases, PhzM is a dimer in solution. The 36 kDa PhzM polypeptide folds into three domains. The C-terminal domain exhibits the alpha/beta-hydrolase fold typical of small molecule methyltransferases. Two smaller N-terminal domains form much of the dimer interface. Structural alignments with known methyltransferases show that PhzM is most similar to the plant O-methyltransferases that are characterized by an unusual intertwined dimer interface. The structure of PhzM contains no ligands, and the active site is open and solvent-exposed when compared to structures of similar enzymes. In vitro experiments using purified PhzM alone demonstrate that it has little or no ability to methylate phenzine-1-carboxylic acid. However, when the putative hydroxylase PhzS is included, pyocyanin is readily produced. This observation suggests that a mechanism has evolved in P. aeruginosa that ensures efficient production of pyocyanin via the prevention of the formation and release of an unstable and potentially deleterious intermediate.

  DOI：

  10.1021/bi6024403
• 作为产物：
  描述：

  5,10-Dihydrophenazine-1-carboxylate 、 氧气 生成 双氧水 、 Phenazine-1-carboxylate
  参考文献：
  名称：

  Trapped intermediates in crystals of the FMN-dependent oxidase PhzG provide insight into the final steps of phenazine biosynthesis

  摘要：

  Phenazines are redox-active secondary metabolites that many bacteria produce and secrete into the environment. They are broad-specificity antibiotics, but also act as virulence and survival factors in infectious diseases. Phenazines are derived from chorismic acid, but important details of their biosynthesis are still unclear. For example, three two-electron oxidations seem to be necessary in the final steps of the pathway, while only one oxidase, the FMN-dependent PhzG, is conserved in the phenazine-biosynthesis phz operon. Here, crystal structures of PhzG from Pseudomonas fluorescens 2-79 and from Burkholderia lata 383 in complex with excess FMN and with the phenazine-biosynthesis intermediates hexahydrophenazine-1,6-dicarboxylate and tetrahydrophenazine-1-carboxylate generated in situ are reported. Corroborated with biochemical data, these complexes demonstrate that PhzG is the terminal enzyme in phenazine biosynthesis and that its relaxed substrate specificity lets it participate in the generation of both phenazine-1,6-dicarboxylic acid (PDC) and phenazine-1-carboxylic acid (PCA). This suggests that competition between flavin-dependent oxidations through PhzG and spontaneous oxidative decarboxylations determines the ratio of PDC, PCA and unsubstituted phenazine as the products of phenazine biosynthesis. Further, the results indicate that PhzG synthesizes phenazines in their reduced form. These reduced molecules, and not the fully aromatized derivatives, are the likely end products in vivo, explaining why only one oxidase is required in the phenazine-biosynthesis pathway.

  DOI：

  10.1107/s0907444913008354

文献信息

• Functional Analysis of Genes for Biosynthesis of Pyocyanin and Phenazine-1-Carboxamide from <i>Pseudomonas aeruginosa</i> PAO1
  作者：Dmitri V. Mavrodi、Robert F. Bonsall、Shannon M. Delaney、Marilyn J. Soule、Greg Phillips、Linda S. Thomashow

  DOI：10.1128/jb.183.21.6454-6465.2001

  日期：2001.11

  Two seven-gene phenazine biosynthetic loci were cloned from Pseudomonas aeruginosa PAO1. The operons, designated phzA1B1C1D1E1F1G1 and phzA2B2C2D2E2F2G2 , are homologous to previously studied phenazine biosynthetic operons from Pseudomonas fluorescens and Pseudomonas aureofaciens . Functional studies of phenazine-nonproducing strains of fluorescent pseudomonads indicated that each of the biosynthetic operons from P. aeruginosa is sufficient for production of a single compound, phenazine-1-carboxylic acid (PCA). Subsequent conversion of PCA to pyocyanin is mediated in P. aeruginosa by two novel phenazine-modifying genes, phzM and phzS , which encode putative phenazine-specific methyltransferase and flavin-containing monooxygenase, respectively. Expression of phzS alone in Escherichia coli or in enzymes, pyocyanin-nonproducing P. fluorescens resulted in conversion of PCA to 1-hydroxyphenazine. P. aeruginosa with insertionally inactivated phzM or phzS developed pyocyanin-deficient phenotypes. A third phenazine-modifying gene, phzH , which has a homologue in Pseudomonas chlororaphis , also was identified and was shown to control synthesis of phenazine-1-carboxamide from PCA in P. aeruginosa PAO1. Our results suggest that there is a complex pyocyanin biosynthetic pathway in P. aeruginosa consisting of two core loci responsible for synthesis of PCA and three additional genes encoding unique enzymes involved in the conversion of PCA to pyocyanin, 1-hydroxyphenazine, and phenazine-1-carboxamide.

  摘要 从铜绿假单胞菌中克隆了两个七基因酚嗪生物合成位点 铜绿假单胞菌 PAO1。这些操作子被命名为 phzA1B1C1D1E1F1G1 和 phzA2B2C2D2E2F2G2 与以前研究过的荧光假单胞菌中的酚嗪生物合成操作子同源。 荧光假单胞菌 和 假单胞菌的酚嗪生物合成操作子。 .对不产酚嗪的荧光假单胞菌菌株进行的功能研究表明，铜绿假单胞菌的每个生物合成操作子都与酚嗪生物合成操作子同源。 铜绿假单胞菌 足以生产单一化合物酚嗪-1-羧酸（PCA）。在铜绿假单胞菌中，酚嗪-1-羧酸（PCA）随后转化为芘花青素的过程是由 铜绿微囊藻 由两个新型酚嗪修饰基因介导、 phzM 和 phzS 分别编码推定的酚嗪特异性甲基转移酶和含黄素单氧化酶。表达 phzS 单独在 大肠杆菌 或酶的情况下，不产生焦花青素的 荧光团 导致 PCA 转化为 1-羟基吩嗪。 铜绿菌 具有插入失活的 phzM 或 phzS 会出现缺乏脓青素的表型。第三个酚嗪修饰基因 phzH 在 假单胞菌中的同源基因 铜绿假单胞菌中也发现了第三个酚嗪修饰基因 phzH，该基因在氯葡萄假单胞菌中也有同源物。 铜绿假单胞菌 PAO1。我们的研究结果表明，在铜绿假单胞菌 PAO1 中存在着一个复杂的芘花青素生物合成途径。 铜绿菌 由负责合成 PCA 的两个核心基因位点和编码参与将 PCA 转化为芘花青素、1-羟基吩嗪和吩嗪-1-甲酰胺的独特酶的另外三个基因组成。
• Crystal Structure of the Pyocyanin Biosynthetic Protein PhzS
  作者：Bryan T. Greenhagen、Katherine Shi、Howard Robinson、Swarna Gamage、Asim K. Bera、Jane E. Ladner、James F. Parsons

  DOI：10.1021/bi702480t

  日期：2008.5.1

  The human pathogen Pseudomonas aeruginosa produces pyocyanin, a blue-pigmented phenazine derivative, which is known to play a role in virulence. Pyocyanin is produced from chorismic acid via the phenazine pathway, nine proteins encoded by a gene cluster. Phenazine-1-carboxylic acid, the initial phenazine formed, is converted to pyocyanin in two steps that are catalyzed by the enzymes PhzM and PhzS. PhzM is an adenosylmethionine dependent methyltransferase, and PhzS is a flavin dependent hydroxylase. It has been shown that PhzM is only active in the physical presence of PhzS, suggesting that a protein-protein interaction is involved in pyocyanin formation. Such a complex would prevent the release of 5-methyl-phenazine-1-carboxylate, the putative intermediate, and an apparently unstable compound. Here, we describe the three-dimensional structure of PhzS, solved by single anomalous dispersion, at a resolution of 2.4 A. The structure reveals that PhzS is a member of the family of aromatic hydroxylases characterized by p-hydroxybenzoate hydroxylase. The flavin cofactor of PhzS is in the solvent exposed out orientation typically seen in unliganded aromatic hydroxylases. The PhzS flavin, however, appears to be held in a strained conformation by a combination of stacking interactions and hydrogen bonds. The structure suggests that access to the active site is gained via a tunnel on the opposite side of the protein from where the flavin is exposed. The C-terminal 23 residues are disordered as no electron density is present for these atoms. The probable location of the C-terminus, near the substrate access tunnel, suggests that it may be involved in substrate binding as has been shown for another structural homologue, RebC. This region also may be an element of a PhzM-PhzS interface. Aromatic hydroxylases have been shown to catalyze electrophilic substitution reactions on activated substrates. The putative PhzS substrate, however, is electron deficient and unlikely to act as a nucleophile, suggesting that PhzS may use a different mechanism than its structural relatives.