Kawashima Tsuyoshi, Aramaki Hironori, Oyamada Tomoya, Makino Kozo, Yamada Mitsugu, Okamura Hideyasu, Yokoyama Katsushi, Ishijima Sanae Arakawa, Suzuki Masashi
National Institute of Advanced Industrial Science and Technology, Tsukuba Center 6-10, Tsukuba, Ibaraki, Japan.
Biol Pharm Bull. 2008 Feb;31(2):173-86. doi: 10.1248/bpb.31.173.
Feast/famine regulatory proteins (FFRPs) comprise a single group of transcription factors systematically distributed throughout archaea and eubacteria. In the eubacterial domain in Escherichia coli, autotrophic pathways are activated and heterotrophic pathways are repressed by an FFRP, the leucine-responsive regulatory protein (Lrp), in some cases in interaction with other transcription factors. By sensing the concentration of leucine, Lrp changes its association state between hexadecamers and octamers to adapt the autotrophic or heterotrophic mode. The lrp gene is regulated so that the concentration of Lrp decreases in the presence of rich nutrition. In the archaeal domain a large part of the metabolism of Pyrococcus OT3 is regulated by another FFRP, FL11. In the presence of rich nutrition, the metabolism is released from repression by FL11; transcription of fl11 is terminated by FL11 forming octamers in interaction with lysine. When the nutrient is depleted, the metabolism is arrested by a high concentration of FL11; FL11 disassembles to dimers in the absence of lysine, and repression of transcription of fl11 is relaxed. Common characteristics of the master regulations by FL11 and Lrp hint at the prototype regulation once achieved in the common ancestor of all extant organisms. Mechanisms of discrimination by FFRPs between DNA sequences and also between co-regulatory molecules, mostly amino acids, and variations of transcription regulations observed with archaea and eubacteria are reviewed.
丰饶/匮乏调节蛋白（FFRPs）是一类转录因子，系统地分布于古细菌和真细菌中。在真细菌结构域的大肠杆菌中，自养途径被一种FFRP（亮氨酸应答调节蛋白，Lrp）激活，而异养途径则被其抑制，在某些情况下，Lrp还会与其他转录因子相互作用。通过感知亮氨酸的浓度，Lrp改变其在十六聚体和八聚体之间的缔合状态，以适应自养或异养模式。lrp基因受到调控，使得在营养丰富时Lrp的浓度降低。在古细菌结构域中，嗜热栖热菌OT3的大部分代谢由另一种FFRP，即FL11调节。在营养丰富时，代谢从FL11的抑制中释放出来；fl11的转录通过FL11与赖氨酸相互作用形成八聚体而终止。当营养耗尽时，高浓度的FL11会使代谢停止；在没有赖氨酸的情况下，FL11解聚为二聚体，fl11转录的抑制作用减弱。FL11和Lrp的主要调控的共同特征暗示了在所有现存生物的共同祖先中曾经实现的原型调控。本文综述了FFRPs在DNA序列之间以及在共同调控分子（主要是氨基酸）之间的区分机制，以及在古细菌和真细菌中观察到的转录调控变化。
