NAD biosynthesis: Identification of the tryptophan to quinolinate pathway in bacteria
NAD biosynthesis: Identification of the tryptophan to quinolinate pathway in bacteria
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DOI：
10.1016/j.chembiol.2003.11.011
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发表时间：
2003-12-01
影响因子：
--
通讯作者：
Begley, TP
中科院分区：
文献类型：
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作者：
Kurnasov, O;Goral, V;Begley, TP
以前的研究已经证明了两种不同的生物合成途径喹啉，普遍从头前体的吡啶环的NAD。在原核生物中，喹啉酸由天冬氨酸和磷酸二羟丙酮形成;在真核生物中，它由色氨酸形成。人们普遍认为，色氨酸到喹啉酸的生物合成途径是唯一的真核生物，然而，本文介绍了使用比较基因组分析，以确定可能的候选人的所有五个基因参与色氨酸到喹啉酸途径在几种细菌。这些基因中的每一个的代表性实例被过表达，并且在每种情况下使用明确的生物化学测定来确认预测的功能。
Previous studies have demonstrated two different bio-synthetic pathways to quinolinate, the universal de novo precursor to the pyridine ring of NAD. In prokaryotes, quinolinate is formed from aspartate and dihydroxyacetone phosphate; in eukaryotes, it is formed from tryptophan. It has been generally believed that the tryptophan to quinolinic acid biosynthetic pathway is unique to eukaryotes; however, this paper describes the use of comparative genome analysis to identify likely candidates for all five genes involved in the tryptophan to quinolinic acid pathway in several bacteria. Representative examples of each of these genes were overexpressed, and the predicted functions are confirmed in each case using unambiguous biochemical assays.