Análise evolutiva das fitocistatinas na linhagem vegetal

Abstract

Cystatins are C1 and C13 cysteine protease inhibitor proteins that act by their reversible binding in the active site of the proteases. Phytocystatins have potential for pest control, environmental resistance to cultivars and in nutraceutica. Given the importance of phytocystatins, the objective of this work was to carry out an in silico evolutionary analysis of these proteins in the plant lineage, searching for cystatins in algae, green algae, bryophytes and pteridophytes. Protein databases encoded by the genomes of 416 species of algae, green algae, bryophytes and pteridophytes obtained from 1000 Plants database, were created for the analyzes. The blastp tool was used along with Blast2GO program to identify the cystatin sequences present in the databases. The conserved domains were also identified. And with MEGAX program, the alignment of the sequences was made using the MUSCLE tool and the construction of phylogenetic trees were performed. Was predicted 36 phytocystatins in green algae, 144 in bryophytes and 68 in pteridophytes, with the amino acids GG, LAxFAV-HN, QVVxG, YEAKVWxPWE and F conversed between them. Phylogenetic trees, indicated a small correlation between phytocystatins found with those observed in higher plants, so it was not possible to classify them using the known phytocystatins classification. This indicates the need for a new classification for this group of inhibitors, including these genes identified in primitive plants.