Evolution of Aromatic Biosynthesis and Regulation in Prokaryotes

詹森博士建议利用 寡核苷酸序列。 核糖体的强保守性 RNA在进化过程中是一个分子组装的基础。 可信的原核生物系统发育树。 缓慢变化 rRNA可以通过SAB值的形式定量， 寡核苷酸编目，从而提供了一个进化的 其他基因产物系统的进化 是可以测量的。 这是第一次有可能 在原核生物中重建进化过程中的事件 生化途径排列与生化途径 调控 我们建议获取数据， 进化的推论， 用于芳香族氨基酸的生物合成。 这将被携带 在原核生物的一个大而易管理的部门中， “紫色”细菌。 已经获得的数据允许建造 关于（i）的演变的演绎的工作模型 酪氨酸途径辅因子特异性，（ii）DAHP合酶 同工酶，（iii）苯丙氨酸途径及其调节， 和（iv）酪氨酸途径及其调节。 随着新 编目数据标识树上的分支位置， 差距限制了解释，我们将继续分析 这些有机体。 在较浅的分歧水平，rRNA/DNA 杂交可能更适合于 进化分歧点的识别 与最近生物化学的微调实例的相关性 变化

Dr. Jensen proposes to utilize the cataloging of oligonucleotide sequence. The strong conservation of ribosomal RNA through evolutionary time is the basis for assembly of a credible phylogenetic tree for prokaryotes. Slow changes in rRNA can be quantitated in the form of SAB values by oligonucleotide cataloging, thus providing an evolutionary scale against which the evolution of other gene-product systems can be measured. It is possible now for the first time to reconstruct in prokaryotes the events in the evolution of biochemical-pathway arrangement and biochemical-pathway regulation. We propose to obtain data that will permit such evolutionary deductions to be made with respect to the pathway for biosynthesis of aromatic amino acids. This will be carried out in a large but manageable division of prokaryotes, the "purple" bacteria. Data already obtained allow construction of a working model for deductions about the evolution of (i) tyrosine-pathway cofactor specificity, (ii) DAHP synthase isozymes, (iii) the phenylalanine pathway and its regulation, and (iv) the tyrosine pathway and its regulation. As new cataloging data identify brance positions on the tree where gaps limit interpretations, we will proceed with analysis of these organisms. At shallow levels of divergence, rRNA/DNA hybridization will probably be more appropriate for identification of evolutionary points of divergence in correlation with fine-tuned instances of recent biochemical change.