Enzymes of the beta-ketoadipate pathway are inducible in Rhizobium and Agrobacterium spp. and constitutive in Bradyrhizobium spp
Enzymes of the beta-ketoadipate pathway are inducible in Rhizobium and Agrobacterium spp. and constitutive in Bradyrhizobium spp
复制标题
β-酮己二酸途径的酶可在根瘤菌和农杆菌属中诱导。
DOI：
10.1128/jb.165.1.288-292.1986
复制
发表时间：
1986
影响因子：
3.2
通讯作者：
L. Ornston
中科院分区：
文献类型：
--
作者：
D. Parke;L. Ornston
原儿茶酸是根瘤菌科成员的通用生长底物，这些细菌通过β-酮己二酸途径利用芳香族化合物。本报告描述了根瘤菌科的不同亚群对催化途径中连续反应的五种酶的转录控制：原儿茶酸加氧酶（EC 1.13.11.3）、β-羧基-顺式，顺式-粘康酸内酯化酶（EC 5.5.1.2）、γ-羧基粘康酸内酯脱羧酶（EC 4.1.1.44）、β-酮己二酸烯醇-内酯水解酶（EC 3.1.1.24）和β-酮己二酸琥珀酰辅酶A转移酶（EC 2.8.3.6）。所有五种酶在快速生长的菌株发根农杆菌、根癌农杆菌、费氏根瘤菌、苜蓿根瘤菌、豆科根瘤菌和三叶根瘤菌中都是可诱导的。在诱导的细胞中的特定活动范围从5- 100倍以上的未诱导的细胞中发现的。与快速生长的菌株和迄今为止研究的所有其他微生物类群的成员相比，缓慢生长的慢生型大豆根瘤菌和豇豆慢生型大豆根瘤菌。组成型表达五种酶中的四种;原儿茶酸加氧酶是该组中唯一的诱导酶。生长缓慢的菌株包括不同的DNA同源性组，所以它似乎可能是组成型表达的四种酶是一个共同的特点，在慢生根瘤菌。这一特性表明芳香族化合物和芳香族催化剂在这些生物的营养中的重要性。
Protocatechuate is a universal growth substrate for members of the family Rhizobiaceae, and these bacteria utilize the aromatic compound via the beta-ketoadipate pathway. This report describes transcriptional controls exercised by different subgroups of the Rhizobiaceae over five enzymes that catalyze consecutive reactions in the pathway: protocatechuate oxygenase (EC 1.13.11.3), beta-carboxy-cis,cis-muconate lactonizing enzyme (EC 5.5.1.2), gamma-carboxymuconolactone decarboxylase (EC 4.1.1.44), beta-ketoadipate enol-lactone hydrolase (EC 3.1.1.24), and beta-ketoadipate succinyl-coenzyme A transferase (EC 2.8.3.6). All five enzymes were inducible in the fast-growing strains Agrobacterium rhizogenes, Agrobacterium tumefaciens, Rhizobium fredii, Rhizobium meliloti, Rhizobium leguminosarum, and Rhizobium trifolii. Specific activities in induced cells ranged from 5- to 100-fold greater than those found in uninduced cells. In contrast to the fast-growing strains and members of every other microbial taxon examined to date, the slow-growing Bradyrhizobium japonicum and cowpea Bradyrhizobium spp. constitutively expressed four of the five enzymes; protocatechuate oxygenase was the only inducible enzyme in this group. The slow-growing strains included different DNA homology groups, so it appears likely that constitutive expression of the four enzymes is a common trait in the bradyrhizobia. This property points to the importance of aromatic compounds and aromatic catabolites in the nutrition of these organisms.