MOLECULAR NOVELTY AND CONSERVATION IN BACTERIAL PROTEIN SEQUENCES

从不同细菌的基因序列推导的蛋白质序列， 古细菌产生了大量关于蛋白质的新知识 功能、相互作用和进化。 一些意想不到的新奇事物 通过包括定向诱变， 光谱/酶学分析和计算机序列分析 数据库。调查结果包括： A. 主要真核生物蛋白质家族的细菌同源物。 的 丝氨酸/苏氨酸蛋白激酶的发现证实了其古老性 蛋白激酶C同系物在蓝藻和古细菌， 除了已知参与细胞分化的那些外， 在粘球菌属中。 TPR重复特征的许多细胞周期蛋白， 在不同的蓝藻和耶尔森氏菌中发现了真核生物 小肠结肠炎 B。 不同的细菌和真核生物的亲核蛋白。 在序列 水平，两个完全不同的，强烈保守的家庭， 蝶呤-钼辅因子酶进行相同的羟基化， （a）古细菌加真细菌和（B）真核生物中的氧化还原反应。 序列特征与蛋白质光谱特性相关 域组织。 C. 复杂细菌中的序列家族。 可用序列来自 多细胞和分化细菌，链霉菌，粘球菌和 各种蓝藻和古细菌，被分类为全球 数据库序列相似性搜索。 百分之50以上的普选 可分类的蛋白质序列在E.杆菌和 其他研究充分的肠道细菌，其中许多具有真核生物 同系物。 项目意义： 基因组序列从代谢和 形态遗传多样的细菌提供了丰富的和具有成本效益的 的分子功能和进化的新发现的来源 proteins.

Protein sequences deduced from gene sequences of diverse bacteria and archaebacteria are yielding a wealth of new knowledge on protein functions, interactions and evolution. A number of unexpected novelties were studied by concerted methods including directed mutagenesis, spectroscopic/enzymological analyses and computer analyses of sequence databases. Findings include:- A. Bacterial homologs of major "eukaryotic" protein families. The antiquity of Serine/Threonine protein kinases was confirmed by discovery of protein kinase C homologs in cyanobacteria and archaebacteria, in addition to those already known to be involved in cellular differentiation in Myxococcus. TPR repeats characteristic of many cell cycle proteins in eukaryotes were found in different cyanobacteria and Yersinia enterocolitica. B. Distinct bacterial and eukaryotic molybdoproteins. At the sequence level, two completely distinct, strongly conserved families of pterin-molybdenum cofactor enzymes perform the same hydroxylation and redox reactions in (a) archaebacteria plus eubacteria and (b) eukaryotes. Sequence features were correlated with protein spectroscopic properties and domain organization. C. Sequence families in complex bacteria. Available sequences from multicellular and differentiating bacteria, Streptomyces, Myxococcus and various cyanobacteria and archaebacteria, were classified by global database sequence similarity searches. More than 50 percent of the classifiable protein sequences did not have counterparts in E. coli and other well-studied enteric bacteria, and many of these had eukaryotic homologs. Significance of project: Genome sequences from metabolically and morphogenetically diverse bacteria provide a rich and cost-effective source of new discoveries on the molecular functions and evolution of proteins.