Question

Carry out a BLAST search against the UniProt database using the following sequence as input: MASTHQSSTEPSSTGKSEETKKDASQGSGQDSKNVTVTKGTGSSATSAAIVKTGGSQGKDSSTTAGSSSTQGQKFSTTPTDPKTFSSDQKEKSKSPAKEVPSGGDSKSQGDTKSQSDAKSSGQSQGQSKDSGKSSSDSSKSHSVIGAVKDVVAGAKDVAGKAVEDAPSIMHTAVDAVKNAATTVKDVASSAASTVAEKVVDAYHSVVGDKTDDKKEGEHSGDKKDDSKAGSGSGQGGDNKKSEGETSGQAESSSGNEGAAPAKGRGRGRPPAAAKGVAKGAAKGAAASKGAKSGAESSKGGEQSSGDIEMADASSKGGSDQRDSAATVGEGGASGSEGGAKKGRGRGAGKKADAGDTSAEPPRRSSRLTSSGTGAGSAPAAAKGGAKRAASSSSTPSNAKKQATGGAGKAAATKATAAKSAASKAPQNGAGAKKKGGKAGGRKRK -- Select from the list below ALL statements that are TRUE. *

• The name of the protein is called DSUP or damage supressor.
• The protein is a highly lethal toxin factor.
• There appears to be only one known example of the protein in the database.
• The protein comes from an organism called a water bear.
• There are at least five other homologs to the protein including egg stalk protein

Answer 1

We are given a protein sequence and asked to run a BLAST program using the Uniprot database. To do this, we need to open the uniprot website and click BLAST . A window would open for us to paste the given sequence after which we would click the "Run BLAST" link at the bottom of the window and wait for the results to appear.

Once the results appear, we can answer the questions based on the results obtained:

• The name of the protein is called DSUP or damage supressor.

The above statement is true. The top of the uniprot results say that the query sequence matches 100% with that of DSUP.

• The protein is a highly lethal toxin factor.

This statement would be false. The description of the DSUP in the database states that the protein protects the DNA of the cell from damage due to environmental stress. So it cannot be a toxin factor.  

• There appears to be only one known example of the protein in the database.

This statement is true. As there is only one result that appeared in the BLAST that matched 100%, the rest were insignificant as they were 25% matches. The 100% match was that of the DSUP protein from Ramazzottius varieornatus , which is commonly known as water bear.

• The protein comes from an organism called a water bear.

This statement is true, as mentioned earlier the protein belongs to the species Ramazzottius varieornatus which is the binomial name for water bear.

• There are at least five other homologs to the protein including egg stalk protein

This statement would be false, as no such information is given in the database pertaining to the structure of the protein, which shows only the DNA and nucleosome binding domains