ARE THERE SIMILAR GENES TO OPSIN?
- A great similarity between two proteins indicates, generally, that they have a common ancestor and may have the same function.
- Two proteins are homolog if they have a common ancestor.
- The search for homolog, that is, evolutionarily related proteins, can be made by comparison with others already deposited in biological databases.
- BLAST (Basic Local Alignment Search Tool) 
- it is one of the most used Bioinformatics programs for identifying similar sequences.
- The BLAST program allows you to submit an unknown sequence and compare it with all sequences in a database, allowing you to discover what possible functions are associated with the unknown sequence.
- In this exercise we suggest that you first find the protein encoded by the nucleotide sequence identified in Activity 2, as having the genetic information for a possible gene. Subsequently, you will use BLAST to check if there is already a similar protein in the database.