Final answer:
The possible explanations include incorrect reading frame, presence of a pseudogene, closer protein sequence match in BLASTP database, different scoring matrix, and different e-value cutoff.
Step-by-step explanation:
The possible explanations for the result shown below are as follows:
- The BLASTX query sequence was translated in all six reading frames, and the top hit was found in a different reading frame than the correct one.
- The BLASTX database contained a pseudogene.
- The BLASTP database contained a protein sequence that was more closely related to the query sequence than any of the protein sequences in the BLASTX database.
- The BLASTX search was performed using a different scoring matrix than the BLASTP search.
- The BLASTX search was performed using a different e-value cutoff than the BLASTP search.