菜豆根瘤菌CFN42全基因组非经典分泌蛋白的预测与分析

Genome-wide Prediction and Analysis of the Non-classical Secreted Proteins of Rhizobium etli CFN42

为了深入了解生物固氮的分子机理,利用Secretome P2.0和Signal P4.1对菜豆根瘤菌CFN42全基因组进行预测,结果发现,在5 963个蛋白质中,非经典分泌蛋白596个,约占总数的10%,主要涉及底物转运,毒力侵染,物质代谢等方面。在有功能描述的215个分泌蛋白中,识别了I、III、IV型分泌系统,这些蛋白质在侵染和根瘤发育方面发挥了重要作用;在381个假定蛋白中,通过结构域分析,发现了Tad、Cupin、Om PA和Csb D结构域,含有这些结构域的非经典分泌蛋白可能参与了根瘤菌的宿主专一性。在豆科植物-根瘤菌固氮体系中,非经典分泌蛋白发挥了重要作用。

In order to further the understanding of the molecular mechanism of the biological nitrogen fixation, we predicted and analyzed the non-classical secreted proteins of Rhizobium etli CFN42 by the softwares of SecretomeP2.0 and SignalP4.1. The results showed that 596 of the 5 963 proteins in CFN42 were non-classical secreted proteins, nearly accounting for 10%of the total number, mainly including substrates transport, virulence infection, and material metabolism etc. We identified type I, III, IV secretion systems among the proteins which were functional annotated, the proteins played an important role in infection and the development of the root nodules. We also found Tad, Cupin, OmPA and CsbD domains by SMART software within the hypothetical proteins, these domain-containing non-classical secreted proteins may participate in the host specificity ofrhizobium. In brief, non-classical proteins play a key role in rhizobium-legume nitrogen fixation system.