Comparison of the amino acid sequences of the transacylase components of branched chain oxoacid dehydrogenase of Pseudomonas putida, and the pyruvate and 2-oxoglutarate dehydrogenases of Escherichia coli.
Comparison of the amino acid sequences of the transacylase components of branched chain oxoacid dehydrogenase of Pseudomonas putida, and the pyruvate and 2-oxoglutarate dehydrogenases of Escherichia coli.
复制标题
恶臭假单胞菌的支链含氧酸脱氢酶与大肠杆菌的丙酮酸和2-氧戊二酸脱氢酶的转酰基酶组分的氨基酸序列的比较。
DOI：
10.1111/j.1432-1033.1988.tb14264.x
复制
发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Sokatch,JR
中科院分区：
文献类型：
--
作者：
Burns,G;Brown,T;Hatter,K;Sokatch,JR
已确定恶臭假单胞菌支链含氧酸脱氢酶的转酰酶组分E2 b的结构基因bkdB的核苷酸序列并翻译成其氨基酸序列。bkdb的起始点是从E2 b的N末端序列中确定的，E2 b是从密切相关的物种铜绿假单胞菌的支链含氧酸脱氢酶中分离出来的。阅读框架由65.5%的G + C组成，82.3%的密码子以G或C结尾。bkdA 2与bkdB之间无基因间隔。没有使用需要次要tRNA的密码子，密码子偏好指数表明优先使用密码子。bkdb基因编码423个氨基酸，但从P.铜绿。SDS/聚丙烯酰胺凝胶电泳测得其相对分子质量为45134（45003减去蛋氨酸）vs 47000。大肠杆菌丙酮酸酯和2-酮戊二酸酯酰基转移酶E2 b中有一个硫辛酰基结构域，而E2 p中有三个硫辛酰基结构域，E2 o中有一个结构域。E2 b的硫辛酰基结构域与E2 p和E2 o的硫辛酰基结构域之间以及E2 b、E2 p和E2 o的E1-E2结合结构域之间存在显著相似性。E2 b的E3结合结构域与E2 p和E2 o之间没有相似性，这可能反映了P的支链含氧酸脱氢酶的E3组分的独特性。putida。从这些比较中得出的结论是，原核丙酮酸、2-酮戊二酸和支链-含氧酸转移酶的转酰基酶可能在大约相同的时间从一个共同的祖先蛋白质进化而来。
The nucleotide sequence ofbkdB, the structural gene for E2b, the transacylase component of branched‐chain‐oxoacid dehydrogenase ofPseudomonas putidahas been determined and translated into its amino acid sequence. The start ofbkdBwas identified from the N‐terminal sequence of E2b isolated from branched‐chain‐oxoacid dehydrogenase of the closely related species,P. aeruginosa. The reading frame was composed of 65.5% G + C with 82.3% of the codons ending in G or C. There was no intergenic space betweenbkdA2andbkdB. No codons requiring minor tRNAs were utilized and the codon bias index indicated a preferential codon usage. ThebkdBgene encoded 423 amino acids although the N‐terminal methionine was absent from E2b prepared fromP. aeruginosa. The relative molecular mass of the encoded protein was 45134 (45003 minus methionine) vs 47000 obtained by SDS/polyacrylamide gel electrophoresis. There was a single lipoyl domain in E2b compared to three lipoyl domains in E2p, and one domain in E2o, the transacylases of pyruvate and 2‐oxoglutarate dehydrogenases ofEscherichia colirespectively. There was significant similarity between the lipoyl domain of E2b and of E2p and E2o as well as between the E1‐E2 binding domains of E2b, E2p and E2o. There was no similarity between the E3 binding domain of E2b to E2p and E2o which may reflect the uniqueness of the E3 component of branched‐chain‐oxoacid dehydrogenase ofP. putida. The conclusions drawn from these comparisons are that the trans‐acylases of prokaryotic pyruvate, 2‐oxoglutarate and branched‐chain‐oxoacid dehydrogenases descended from a common ancestral protein probably at about the same time.