高等植物中的RNA聚合酶I。变构调节以及与控制NTP库的核磷酸酶活性相互作用的证据。
RNA polymerase I from higher plants. Evidence for allosteric regulation and interaction with a nuclear phosphatase activity controlled NTP pool.
作者信息
Grossmann K, Seitz U
出版信息
Nucleic Acids Res. 1979 Dec 11;7(7):2015-29. doi: 10.1093/nar/7.7.2015.
RNA polymerase I was isolated from parsley cells grown in suspension culture and from soybean hypocotyls. Kinetic studies of the enzyme revealed that RNA polymerase I is an allosteric regulated enzyme. The enzyme activity was influenced by nucleoside triphosphates (NTP) and divalent cations. NTP exceeding a 1:1 ratio of these two components acted as allosteric inhibitors, contrary to free divalent cations, which had promotive effects on the RNA polymerase I. Furthermore, isolated nuclei from parsley exhibited a powerful nucleoside triphosphatase (NTPase) activity. Contrary to RNA polymerase I, this enzyme was stimulated by NTP exceeding the 1:1 ratio of NTP and divalent cations. Free divalent cations had an inhibitory effect. Assuming that a causal connection of these two processes does exist, a possible role of this NTPase would be the control of NTP pools in relation to divalent cations and thus regulating RNA synthesis.
从悬浮培养的芹菜细胞和大豆下胚轴中分离出RNA聚合酶I。对该酶的动力学研究表明，RNA聚合酶I是一种别构调节酶。酶活性受核苷三磷酸（NTP）和二价阳离子的影响。当NTP与这两种成分的比例超过1:1时，NTP作为别构抑制剂起作用，这与游离二价阳离子相反，游离二价阳离子对RNA聚合酶I有促进作用。此外，从芹菜中分离出的细胞核表现出强大的核苷三磷酸酶（NTPase）活性。与RNA聚合酶I相反，当NTP与二价阳离子的比例超过1:1时，该酶受到刺激。游离二价阳离子具有抑制作用。假设这两个过程确实存在因果关系，那么这种NTPase的一个可能作用是控制与二价阳离子相关的NTP库，从而调节RNA合成。
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