Functional analysis of genes for biosynthesis of pyocyanin and phenazine-1-carboxamide from Pseudomonas aeruginosa PAO1
Functional analysis of genes for biosynthesis of pyocyanin and phenazine-1-carboxamide from Pseudomonas aeruginosa PAO1
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DOI：
10.1128/jb.183.21.6454-6465.2001
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发表时间：
2001-11-01
影响因子：
3.2
通讯作者：
Thomashow, LS
中科院分区：
文献类型：
--
作者：
Mavrodi, DV;Bonsall, RF;Thomashow, LS
从铜绿假单胞菌PAO1中克隆了两个吩嗪生物合成基因座。这些操纵子分别命名为phzA1B1C1D1E1F1G1和phzA2B2C2D2E2F2G2，与以前研究过的荧光假单胞菌吩嗪生物合成操纵子同源。和金黄色假单胞菌。对不产吩嗪的荧光假单胞菌的功能研究表明，铜绿假单胞菌的每个生物合成操纵子足以产生一种化合物吩嗪-L-羧酸(PCA)。在铜绿假单胞菌中，PCA的后续转化是由两个新的吩嗪修饰基因phzM和phzS介导的，这两个基因分别编码吩嗪专一性甲基转移酶和含黄素的单加氧酶。在大肠杆菌中单独表达phzS或在酶中表达，不产生绿青素的荧光假单胞菌可将PCA转化为1-羟基吩嗪。插入失活phzM或phzS的铜绿假单胞菌产生绿脓素缺乏表型。第三个吩嗪修饰基因phzH与绿假单胞菌的同源基因phzH也被发现，并被证明控制铜绿假单胞菌PAO1中PCA合成吩嗪-1-甲酰胺。结果表明，在铜绿假单胞菌PAO1中存在一个复杂的绿青素生物合成途径，包括两个负责PCA合成的核心基因和另外三个编码PCA转化为绿青素的独特酶、1-羟基吩嗪和吩嗪-1-甲酰胺的基因。
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-l-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.