Molecular characterization of the unusual peptide CORO1C-47aa encoded by the circular RNA and docking simulations with its binding partner.

Circular RNAs, which have covalently closed ends, are in the class of non-coding RNAs. Recent studies reveal that they are associated with various biochemical pathways. One such involvement of circular RNAs is in the onset of different types of cancers. Though the circular RNAs are known as non-coding RNAs, some of them are found to possess the capacities to code for proteins. One such circular RNA is hsa-circ-0000437 which is known to code for a short peptide referred to as CORO1C-47aa. The peptide has anti-angiogenic activity and is associated with the prevention of endometrial cancer. The peptide binds to the PAS-B domain of the Aryl hydrocarbon Receptor Nuclear Translocator (ARNT). However, till date only the amino acid sequence of the peptide is known and no structural details of the peptide are available. Therefore, in this work, our aim was to predict how the peptide would fold and what could be its possible ligand binding sites. We used computational tools to determine the structure of the peptide refined further by molecular dynamics simulations. We then performed molecular docking simulations of the peptide with its known binding partner ARNT to gain an insight into the modes of binding as the process is associated with endometrial cancer. The possible ligand binding sites along-with the natures of the possible other different ligands of the peptide were analyzed further. From this structure function analysis study, we tried to elucidate the plausible mechanism of the involvements of the peptide in the onset of endometrial cancer. This is the first report on the structural characterization of the peptide and its modes of interactions with the partner protein ARNT. This study may therefore be useful in determining the structures of new drug candidates for the treatment of endometrial cancer.