T4 Phage dNTP Synthetase, a Multienzyme Complex for Dexyribonucleotide

本研究的长期目标是：(1)了解DNA前体生物合成是如何被调控的；(2)了解影响DNA前体合成的调控机制如何控制DNA复制的速率和保真度；(3)了解DNA前体生物合成紊乱的代谢和遗传后果；(4)有助于理解所涉及的酶的作用机制。拟议的研究涉及在T4噬菌体感染的大肠杆菌中形成的多酶复合物，该复合物进行脱氧核糖核苷三磷酸（dNTPs）的合成。这是T4 dNTP合成酶复合物。丰富的T4基因和生化知识使我们有多种有效的方法来理解该系统中的蛋白-蛋白相互作用。DNA复制使用前体，脱氧核糖核苷三磷酸，专门用于这一目的，几乎没有其他用途。。除了复制外，dNTPs还用于DNA修复和重组；细菌也利用dTTP合成细胞壁。这种有限的代谢作用使得DNA合成在前体形成水平上被特异性调节成为可能。本研究试图描述dNTP的合成是如何被控制的，以及这些机制对DNA复制控制的贡献。

The long-range goals of this research are (1) to understand how DNA precursor biosynthesis is regulated; (2) to understand how regulatory mechanisms affecting DNA precursor synthesis control the rate and fidelity of DNA replication; (3) to understand the metabolic and genetic consequences of pertubations in DNA precursor biosynthesis; and (4) to contribute toward an understanding of mechanisms of action of the enzymes involved. The proposed research involves a multienzyme complex, formed in T4 phage- infected Escherichia coli, which carries out the synthesis of deoxyribonucleoside triphosphates (dNTPs). This is the T4 dNTP synthetase complex. The wealth of genetic and biochemical knowledge of T4 permits a variety of powerful approaches to understanding protein-protein interactions in this system. %%% DNA replication uses precursors, the deoxyribonucleoside triphosphates, which are specialized for that purpose and for little else. In addition to replication, dNTPs are used in DNA repair and in recombination; also, bacteria used dTTP in cell wall synthesis. This limited repertoire of metabolic role makes it possible for DNA synthesis to be regulated specifically at the level of precursor formation. This research attempts to describe how dNTP synthesis is controlled and the extend to which these mechanisms contribute toward the control of DNA replication.