Panina E M, Vitreschak A G, Mironov A A, Gelfand M S
Department of Mathematics, Moscow State University, Russia.
J Mol Microbiol Biotechnol. 2001 Oct;3(4):529-43.
Computational comparative techniques were applied to analysis of the aromatic amino acid regulons in gamma-proteobacteria. This resulted in characterization of the TrpR and TyrR regulons in the genomes of Yersinia pestis, Haemophilus influenzae, Vibrio cholerae and other bacteria and identification of new members of the PhhR regulon in the genome of Pseudomonas aeruginosa. Candidate attenuators were constructed for all studied genomes, including the trpBA operon of the very distantly related bacterium Chlamidia trachomatis. The pheA attenuator of Y. pestis is an integration site for the insertion element IS-200. It was shown that the triplication of the DAHP-synthase genes occurred prior to the divergence of families Enterobacteriaceae, Vibrionaceae and Alteromonadaceae. The candidate allosteric control site of the DAHP-syntheases was identified. This site is deteriorated in AroH of Buchnera sp. APS. The known DAHP-synthase of Bordetella pertussis is likely to be feedback-inhibited by phenylalanine, and the DAHP-synthase of Corynebacterium glutamicum could be inhibited by tyrosine. Overall, the most extensive regulation was observed in Escherichia coli, whereas the regulation in other genomes seems to be less developed. At the extreme, the tryptophan production in the aphid endosymbiont Buchnera sp. APS is free from transcriptional, attenuation, and allosteric control.
计算比较技术被应用于分析γ-变形菌中的芳香族氨基酸调控子。这使得在鼠疫耶尔森菌、流感嗜血杆菌、霍乱弧菌和其他细菌的基因组中对TrpR和TyrR调控子进行了表征，并在铜绿假单胞菌的基因组中鉴定出了PhhR调控子的新成员。为所有研究的基因组构建了候选衰减子，包括亲缘关系极远的细菌沙眼衣原体的trpBA操纵子。鼠疫耶尔森菌的pheA衰减子是插入元件IS-200的整合位点。结果表明，DAHP合酶基因的三倍化发生在肠杆菌科、弧菌科和交替单胞菌科分化之前。确定了DAHP合酶的候选别构控制位点。该位点在布赫纳菌属APS的AroH中已退化。已知百日咳博德特氏菌的DAHP合酶可能受到苯丙氨酸的反馈抑制，而谷氨酸棒杆菌的DAHP合酶可能受到酪氨酸的抑制。总体而言，在大肠杆菌中观察到了最广泛的调控，而在其他基因组中的调控似乎不太发达。在极端情况下，蚜虫内共生菌布赫纳菌属APS中的色氨酸产生不受转录、衰减和别构控制。
