Souza Diorge Paulo de, Silva Simoneide Souza, Baptista Alessandra J, Nicola André Moraes, Kyaw Cynthia M, Silva-Pereira Ildinete
Instituto de Biologia, Departamento de Biologia Celular, Universidade de Brasília, Campus Universitário Darcy Ribeiro, Asa Norte, 70910-900 Brasília, DF, Brazil.
Genet Mol Res. 2005 Jun 30;4(2):273-89.
The translational and post-translational modification machineries of Paracoccidioides brasiliensis were assessed by means of comparative analyses of PbAESTs (P. brasiliensis assembled expressed sequence tags) with sequences deposited on different databases. Of the 79 sequences corresponding to cytosolic ribosomal proteins, we were able to find 78 in the P. brasiliensis transcriptome. Nineteen of the 27 Saccharomyces cerevisiae genes related to translation initiation were also found. All eukaryotic elongation factors were detected in P. brasiliensis transcriptome, with eEF1A as one of the most expressed genes. Translation termination is performed, in eukaryotes, by factors 1 and 3 (eRF1, eRF3). In P. brasiliensis transcriptome it was possible to identify eRF3, but not eRF1. Sixteen PbAESTs showing aminoacyl-tRNA synthetase-predicted activities were found in our analyses, but no cysteinyl-, leucyl-, asparagyl- and arginyl-tRNA synthetases were detected. Among the mitochondrial ribosomal proteins, we have found 20 and 18 orthologs to S. cerevisiae large and small ribosomal subunit proteins, respectively. We have also found three PbAESTs similar to Neurospora crassa mitochondrial ribosomal genes, with no similarity with S. cerevisiae genes. Although orthologs to S. cerevisiae mitochondrial EF-Tu, EF-G and RF1 have been found in P. brasiliensis transcriptome, no sequences corresponding to functional EF-Ts were detected. In addition, 64 and 28 PbAESTs associated to protein modification and degradation, respectively, were found. These results suggest that these machineries are well conserved in P. brasiliensis, when compared to other organisms.
通过将巴西副球孢子菌组装表达序列标签（PbAESTs）与不同数据库中存储的序列进行比较分析，评估了巴西副球孢子菌的翻译和翻译后修饰机制。在79个对应于胞质核糖体蛋白的序列中，我们在巴西副球孢子菌转录组中找到了78个。在与翻译起始相关的27个酿酒酵母基因中，也发现了19个。在巴西副球孢子菌转录组中检测到了所有真核生物延伸因子，其中eEF1A是表达量最高的基因之一。在真核生物中，翻译终止由因子1和3（eRF1、eRF3）执行。在巴西副球孢子菌转录组中能够鉴定出eRF3，但未鉴定出eRF1。在我们的分析中发现了16个显示氨酰-tRNA合成酶预测活性的PbAESTs，但未检测到半胱氨酰、亮氨酰、天冬氨酰和精氨酰-tRNA合成酶。在线粒体核糖体蛋白中，我们分别发现了20个和18个与酿酒酵母大、小核糖体亚基蛋白的直系同源物。我们还发现了3个与粗糙脉孢菌线粒体核糖体基因相似的PbAESTs，与酿酒酵母基因无相似性。虽然在巴西副球孢子菌转录组中发现了与酿酒酵母线粒体EF-Tu、EF-G和RF1的直系同源物，但未检测到与功能性EF-Ts对应的序列。此外，分别发现了64个和28个与蛋白质修饰和降解相关的PbAESTs。这些结果表明，与其他生物相比，这些机制在巴西副球孢子菌中保存良好。
