Hannaert V, Opperdoes F R, Michels P A
Research Unit for Tropical Diseases, Christian de Duve Institute of Cellular Pathology (ICP), and Laboratory of Biochemistry, Catholic University of Louvain, Brussels, Belgium.
J Mol Evol. 1998 Dec;47(6):728-38. doi: 10.1007/pl00006432.
In this work, we present the sequences and a comparison of the glycosomal GAPDHs from a number of Kinetoplastida. The complete gene sequences have been determined for some species (Crithidia fasciculata, Herpetomonas samuelpessoai, Leptomonas seymouri, and Phytomonas sp), whereas for other species (Trypanosoma brucei gambiense, Trypanosoma congolense, Trypanosoma vivax, and Leishmania major), only partial sequences have been obtained by PCR amplification. The structure of all available glycosomal GAPDH genes was analyzed in detail. Considerable variations were observed in both their nucleotide composition and their codon usage. The GC content varies between 64.4% in L. seymouri and 49.5% in the previously sequenced GAPDH gene from Trypanoplasma borreli. A highly biased codon usage was found in C. fasciculata, with only 34 triplets used, whereas in T. borreli 57 codons were employed. No obvious correlation could be observed between the codon usage and either the nucleotide composition or the level of gene expression. The glycosomal GAPDH is a very well-conserved enzyme. The maximal overall difference observed in the amino acid sequences is only 25%. Specific insertions and extensions are retained in all sequences. The residues involved in catalysis, substrate, and inorganic phosphate binding are fully conserved, whereas some variability is observed in the cofactor-binding pocket. The implications of these data for the design of new trypanocidal drugs targeted against GAPDH are discussed. All available gene and amino acid sequences of glycosomal GAPDHs were used for a phylogenetic analysis. The division of the Kinetoplastida into two suborders, Bodonina and Trypanosomatina, was well supported. Within the letter group, the Trypanosoma species appeared to be monophyletic, whereas the other trypanosomatids form a second clade.
在这项工作中，我们展示了多个动质体目生物的糖体甘油醛-3-磷酸脱氢酶（GAPDH）的序列及比较结果。已确定了一些物种（fasiculata短膜虫、samuelpessoai赫氏锥虫、seymouri细滴虫和Phytomonas sp）的完整基因序列，而对于其他物种（布氏冈比亚锥虫、刚果锥虫、活泼锥虫和硕大利什曼原虫），仅通过聚合酶链反应（PCR）扩增获得了部分序列。对所有可用的糖体GAPDH基因结构进行了详细分析。在其核苷酸组成和密码子使用方面均观察到了相当大的差异。GC含量在seymouri细滴虫中的为64.4%，而在先前测序的博氏锥虫GAPDH基因中的为49.5%。在fasiculata短膜虫中发现密码子使用存在高度偏向性，仅使用了34个三联体，而在博氏锥虫中使用了57个密码子。未观察到密码子使用与核苷酸组成或基因表达水平之间存在明显相关性。糖体GAPDH是一种高度保守的酶。在氨基酸序列中观察到的最大总体差异仅为25%。所有序列中都保留了特定的插入和延伸。参与催化、底物和无机磷酸结合的残基完全保守，而在辅因子结合口袋中观察到了一些变异性。讨论了这些数据对设计针对GAPDH的新型抗锥虫药物的意义。使用糖体GAPDH的所有可用基因和氨基酸序列进行了系统发育分析。动质体目分为两个亚目，波豆亚目和动基体亚目，这一分类得到了有力支持。在后者这个类群中，锥虫属物种似乎是单系的，而其他锥虫目生物形成了第二个分支。
