4-HYDROXYBENZOATE-COENZYME-A LIGASE FROM RHODOPSEUDOMONAS-PALUSTRIS - PURIFICATION, GENE SEQUENCE, AND ROLE IN ANAEROBIC DEGRADATION
4-HYDROXYBENZOATE-COENZYME-A LIGASE FROM RHODOPSEUDOMONAS-PALUSTRIS - PURIFICATION, GENE SEQUENCE, AND ROLE IN ANAEROBIC DEGRADATION
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DOI：
10.1128/jb.176.3.634-641.1994
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发表时间：
1994-02-01
影响因子：
3.2
通讯作者：
HARWOOD, CS
中科院分区：
文献类型：
--
作者：
GIBSON, J;DISPENSA, M;HARWOOD, CS
大多数芳香酸的厌氧代谢是由辅酶A硫酯的形成引发的。沼泽红球藻在厌氧光养条件下生长良好，有许多芳香酸，包括苯甲酸和4-羟基苯甲酸，作为碳源。从4-羟基苯甲酸盐培养的红曲霉细胞中纯化出一种能与4-羟基苯甲酸盐反应的辅酶A连接酶。沼泽这种酶需要MgATP、还原型辅酶A和4-羟基苯甲酸酯、苯甲酸酯或环己-1，4-二烯羧酸酯以获得最佳活性，但也以较低的速率使用磷酸泛酰巯基乙胺、环己-2，5-二烯羧酸酯和对氟苯甲酸酯。4-羟基苯甲酸-辅酶A连接酶的分子特征不同于先前描述的来自R. palustris，两种连接酶没有交叉反应的免疫。对编码4-羟基苯甲酸酶的基因进行克隆和测序。推导的基因产物与参与芳香酸好氧降解的细菌辅酶A连接酶具有约20%的氨基酸同源性。火箭筒携带破坏的4-羟基苯甲酸-辅酶A连接酶基因的palustris突变体不能在厌氧条件下与对羟基苯甲酸一起生长，表明该酶是该化合物厌氧降解所必需的。
Anaerobic metabolism of most aromatic acids is initiated by coenzyme A thioester formation. Rhodopseudomonas palustris grows well under anaerobic, phototrophic conditions with many aromatic acids, including benzoate and 4-hydroxybenzoate, as a carbon source. A coenzyme A ligase that reacts with 4-hydroxybenzoate was purified from 4-hydroxybenzoate-grown cells of R. palustris. This enzyme required MgATP, reduced coenzyme A, and 4-hydroxybenzoate, benzoate, or cyclohex-1,4-dienecarboxylate for optimal activity but also used phosphopantetheine, cyclohex-2,5-dienecarboxylate, and il-fluorobenzoate at lower rates. The 4-hydroxybenzoate-coenzyme A ligase differed in molecular characteristics from a previously described benzoate-coenzyme A ligase from R. palustris, and the two ligases did not cross-react immunologically. The gene encoding the 4-hydroxybenzoate enzyme was cloned and sequenced. The deduced gene product showed about 20% amino acid identity with bacterial coenzyme A ligases involved in aerobic degradation of aromatic acids. An R. palustris mutant carrying a disrupted 4-hydroxybenzoate-coenzyme A ligase gene was unable to grow with il-hydroxybenzoate under anaerobic conditions, indicating that the enzyme is essential for anaerobic degradation of this compound.