Structural and Functional Characterization of YdjI, an Aldolase of Unknown Specificity in <i>Escherichia coli</i> K12
作者:Jamison P. Huddleston、James B. Thoden、Brandon J. Dopkins、Tamari Narindoshvili、Blair J. Fose、Hazel M. Holden、Frank M. Raushel
DOI:10.1021/acs.biochem.9b00326
日期:2019.8.6
cluster is found in 80% of sequenced Escherichia coli genomes and other closely related species in the human microbiome. On the basis of the annotations of the enzymes located in this cluster, it is expected that together they catalyze the catabolism of an unknown carbohydrate. The focus of this investigation is on YdjI, which is in the ydj gene cluster of E. coli K-12. It is predicted to be a class
该YDJ基因簇的测序的80%中发现大肠杆菌的基因组和人类微生物等密切相关的物种。基于位于该簇中的酶的注释,预期它们一起催化未知碳水化合物的分解代谢。这项研究的重点是YdjI,它位于大肠杆菌K-12的ydj基因簇中。据预测是未知功能的II类醛缩酶。在这里,我们描述了这种酶的结构和功能表征。YdjI催化亲的氢/氘交换小号氢在磷酸二羟基丙酮酯(DHAP)的C3。在DHAP存在下,YdjI催化与多种醛糖的醛醇缩合。YdjI对具有特定羟基立体化学和带负电荷的末端(羧酸根或磷酸根)的高阶(七碳,八碳和九碳)单糖表现出强烈的偏爱。最好的底物是l-阿拉伯糖醛酸,表观k cat为3.0 s –1。该产品,升-甘油基-升-半乳-octuluronate -1-磷酸,具有ķ猫/ ķ米的2.1×10值3中号-1小号-1与YdjI后向醛醇缩合反应。这是第一次记录合成升-甘油基-升-半乳-octuluronate -