Bacteriology Group, International Centre for Genetic Engineering & Biotechnology, Trieste, Italy.
Phytopathology. 2010 Mar;100(3):262-70. doi: 10.1094/PHYTO-100-3-0262.
Chorismate mutase (CM) is a key enzyme in the shikimate pathway which is responsible for the synthesis of aromatic amino acids. There are two classes of CMs, AroQ and AroH, and several pathogenic bacteria have been reported to possess a subgroup of CMs designated AroQ(gamma). These CMs are usually exported to the periplasm or outside the cell; in a few cases, they have been reported to be involved in virulence and their precise role is currently unknown. Here, we report that the important rice pathogen Xanthomonas oryzae pv. oryzae XKK.12 produces an AroQ(gamma) CM which we have purified and characterized from spent supernatants. This enzyme is synthesized in planta and X. oryzae pv. oryzae knock-out mutants are hypervirulent to rice. The role of this enzyme in X. oryzae pv. oryzae rice virulence is discussed.
分支酸变位酶（CM）是莽草酸途径中的一种关键酶，负责芳香族氨基酸的合成。CM 有两类，AroQ 和 AroH，有报道称几种致病菌拥有一组被指定为 AroQ(gamma)的 CM。这些 CM 通常被输出到周质或细胞外；在少数情况下，它们被报道与毒力有关，但其确切作用目前尚不清楚。在这里，我们报告称，重要的水稻病原体稻黄单胞菌 pv. 稻生致病变种 XKK.12 产生一种 AroQ(gamma)CM，我们已从废弃的上清液中纯化并对其进行了表征。这种酶是在植物体内合成的，稻黄单胞菌 pv. 稻生致病变种敲除突变体对水稻具有超毒性。我们讨论了该酶在稻黄单胞菌 pv. 稻生致病变种水稻毒性中的作用。
