NEW FEATURES OF REGULATION OF TRYPTOPHAN OPERON
NEW FEATURES OF REGULATION OF TRYPTOPHAN OPERON
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DOI：
10.1126/science.1094538
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发表时间：
1975-01-01
期刊：
影响因子：
56.9
通讯作者：
YANOFSKY, C
中科院分区：
文献类型：
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作者：
BERTRAND, K;KORN, L;YANOFSKY, C
1961年，Jacob和Monod(1)详细描述了他们的乳糖(Lac)操纵子表达调控模型，在该模型中，抑制子分子作用于DNA上的操纵子(操纵子)位置，通过RNA聚合酶调节操纵子的转录。虽然他们模型的基本方面已经被广泛的遗传和生化研究证实(2)，但最近对lac操纵子的研究揭示了这个基因簇的调控比最初认为的更复杂。还有第二种调节机制，分解代谢抑制，也直接影响操纵子的表达(3)。此外，对其他特征良好的系统的研究，如大肠杆菌的L-阿拉伯糖操纵子(4)以及鼠伤寒沙门氏菌和产气克雷伯氏菌的组氨酸降解操纵子(5)，发现了不能用阻遏-操纵子模型调节的调节特征。在这些情况下，似乎除了抑制子-操纵子相互作用和分解代谢抑制外，还使用其他机制来调节操纵子的表达。这些研究的教训是，任何基因或操纵子的表达调控可能涉及抑制以外的机制，将控制与其他细胞过程相结合。对大肠杆菌色氨酸(Trp)操纵子的研究使我们相信，操纵子和抑制子(6，7)之间的相互作用和最终产物抑制(8)可以充分解释色氨酸生物合成的调控。这一观点最近被一项意想不到的发现动摇了(9)，即具有Trp操纵子某些内部缺失的突变体在...
In 1961 Jacob and Monod (1) presented a detailed description of their model for the regulation of expression of the lactose (lac) operon of Escherichia coli, in which a repressor molecule acted at a site on the DNA, the operator, to regulate transcription of the operon by RNA polymerase. Although the fundamental aspects of their model have been substantiated by extensive genetic and biochemical investigations (2), more recent studies with the lac operon have revealed that regulation of this gene cluster is more complex than originally thought. There is a second regulatory mechanism, catabolite repression, that also directly influences operon expression (3). Furthermore, investigations with other well-characterized systems such as the L-arabinose operon of E. coli (4) and the histidine degradation operons (5) of Salmonella typhimurium and Klebsiella aerogenes have uncovered regulatory features that cannot be accommodated in a repressor-operator model of regulation. In these cases, it appears that in addition to repressor-operator interactions, and catabolite repression, other mechanisms are used to regulate operon expression. The lesson from these studies is that regulation of expression of any gene or operon may involve mechanisms other than repression which integrate control with other cellular processes.Studies with the tryptophan (trp) operon of E. coli led us to believe that interaction between operator and repressor (6, 7) and end product inhibition (8) could adequately explain regulation of tryptophan biosynthesis. This view was shaken re-cently by the unexpected finding (9) that mutants with certaininternal deletions in the trp operon showed significantly in-