CONTROL OF META-CLEAVAGE DEGRADATION OF 4-HYDROXYPHENYLACETATE IN PSEUDOMONAS-PUTIDA
CONTROL OF META-CLEAVAGE DEGRADATION OF 4-HYDROXYPHENYLACETATE IN PSEUDOMONAS-PUTIDA
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DOI：
10.1128/jb.147.3.844-850.1981
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发表时间：
1981-01-01
影响因子：
3.2
通讯作者：
BAYLY, RC
中科院分区：
文献类型：
--
作者：
BARBOUR, MG;BAYLY, RC
研究了恶臭假单胞菌野生型菌株P23XI(NCIB 9865)和结构基因突变或调节基因突变突变菌株4-羟基苯乙酸异裂解途径酶的合成。对突变株的诱导研究表明，4-羟基苯乙酸酯诱导产生羟基酶，3，4-二羟基苯乙酸酯诱导产生2，3-加氧酶、乙醛脱氢酶、异构酶、脱羧酶和水合酶。这表明羟基酶结构基因不存在于包含这一元途径的任何其他结构基因的操纵子中。对合成2，3-加氧酶和后续酶的突变菌株的研究表明，这些酶的合成调节是一致的，并且在这些菌株中，羟基酶只是可诱导的。对一个缺乏2，3-加氧酶活性的假定的极性突变体进行的观察表明，编码该酶的结构基因和该途径的后续酶存在于同一操纵子中。对一株在诱导2，3-加氧酶和后续酶方面存在缺陷的调节突变株的研究表明，2，3-加氧酶操纵子处于阳性控制之下。
Synthesis of enzymes of the 4-hydroxyphenylacetate meta-cleavage pathway was studied in P. putida wild-type strain P23XI (NCIB 9865) and mutant strains which had either structural or regulatory gene mutations. Induction studies with mutant strains each defective in an enzyme of the pathway showed that 4-hydroxyphenylacetate induced the hydroxylase and that 3,4-dihydroxyphenylacetate induced the 2,3-oxygenase, aldehyde dehydrogenase, isomerase, decarboxylase and hydratase. This showed that the hydroxylase structural gene does not exist in an operon that contains any other structural gene of this meta pathway. Studies of mutant strains that synthesized constitutively the 2,3-oxygenase and subsequent enzymes suggested that the regulation of synthesis of these enzymes was coincident, and, in such strains, the hydroxylase was inducible only. Observations made with a putative polarity mutant that lacked 2,3-oxygenase activity suggested that the structural genes encoding this enzyme and subsequent enzymes of the pathway exist in the same operon. Studies of a regulatory mutant strain that was defective in the induction of the 2,3-oxygenase and subsequent enzymes suggest that the 2,3-oxygenase operon is under positive control.