Selenoproteins are a type of protein present in all three domains of life that contain an amino acid called selenocysteine (Sec) in its structure. The molecular structure of selenocysteine is an analogue of the amino acid cysteine in which sulphur atom has been replaced by a selenium atom [1].

Selenienium is required for life as is an essential component of several major metabolic pathways, including thyroid hormone metabolism, antioxidant defence systems, and immune function [2].

Incorporation of Sec into selenoproteins employs a unique mechanism that involves decoding of the UGA codon, which usually functions as a Stop codon. This process requires multiple features such as the selenocysteine insertion sequence (SECIS) element and several protein factors including a specific elongation factor eFSec and the SECIS binding protein 2, SBP2 [3].

Although the basic mechanisms of Sec synthesis and insertion into proteins in both prokaryotes and eukaryotes have been studied in detail, the identity and functions of many selenoproteins remain largely unknown [4].

The objective of this project was to characterize the selenoproteome in Trichechus manatus latirostris through an homologous comparison with Loxodonta africana (elephant), which is one of the best-characterized phylogenetically closest organisms. For some proteins were not capable of using this species so we performed the analogy with Homo sapiens (human).

In order to predict the selenoproteins of this organism we used some bioinformatics tools. We used some sequencing alignment programs, such as blast; gen prediction programs, such as exonerate; and protein-homology comparison programs, such as t-coffee. In addition, we predict the elements SECI through the program SeciSearch3.0 and Seblastian to support the outcome of the prediction of selenoproteins.

From our results we have been able to predict 21 selenoproteins. We have also characterized 6 related amino acid Sec insertion machinery.

This website contains the description of the project we have undertaken/performed to characterize the selenoproteins present in the genome of Trichechus manatus latirostris , as well as their synthesis machinery. We describe the methodology and results obtained. We also interpret and evaluate these results in the discussion in detail. Finally, we perform a conclusion to sum-up the main points and to elucidate the purpose and the findings of our work.