Análise comparativa das estruturas primárias e terciárias de proteínas de movimento de vírus

Abstract

The success of the parasitism by viruses depends on the use of host metabolism to generate new infectious particles and transmit them to other cells. In plant viruses, intercellular transport is mediated by movement proteins (MPs) that interact with host communication channels (plasmodesmata) by different mechanisms resulting in systemic infection. Comparative analysis between structures of viral proteins allow to understand their functional and evolutionary relationships, however, few comparative studies are available involving MPs of different viral taxonomic categories. Therefore, the aims of this study were to verify if there is conservation of the primary and tertiary structures of movement proteins among viral isolates from different groups, using as reference the comparisons of replicases or replication-associated proteins and; to verify if there is correlation between the mechanism of interaction with plasmodesmata and the structural similarity of MPs. Amino acid sequences of replicases/replication-associated and movement proteins were obtained from 44 isolates of different viral genera and comparative analyses of the primary structures were performed using the EMBOSS-Needle program and the tertiary structures were obtained using I-TASSER program and compared in the UFSC Chimera program. In general, there is a low degree of conservation of the tertiary structure of MPs and proteins from isolates belonging to different taxonomic categories may show structural similarity, including at the level of viral domains. Therefore, the conservation of primary and tertiary structures of MPs does not depend on their viral taxonomic categories and there is no correlation between similarity of their three-dimensional structures and the mechanisms of interaction with plasmodesmata.