Task 2: Multiple Sequence Alignment

We researched the protein sequence of the branched-chain alpha-keto acid dehydrogenase complex subunit alpha (BCKDHA) with the following original sequence:

• BCKDHA

>sp|P12694|ODBA_HUMAN 2-oxoisovalerate dehydrogenase subunit alpha, mitochondrial OS=Homo sapiens GN=BCKDHA PE=1 SV=2
MAVAIAAARVWRLNRGLSQAALLLLRQPGARGLARSHPPRQQQQFSSLDDKPQFPGASAE
FIDKLEFIQPNVISGIPIYRVMDRQGQIINPSEDPHLPKEKVLKLYKSMTLLNTMDRILY
ESQRQGRISFYMTNYGEEGTHVGSAAALDNTDLVFGQYREAGVLMYRDYPLELFMAQCYG
NISDLGKGRQMPVHYGCKERHFVTISSPLATQIPQAVGAAYAAKRANANRVVICYFGEGA
ASEGDAHAGFNFAATLECPIIFFCRNNGYAISTPTSEQYRGDGIAARGPGYGIMSIRVDG
NDVFAVYNATKEARRRAVAENQPFLIEAMTYRIGHHSTSDDSSAYRSVDEVNYWDKQDHP
ISRLRHYLLSQGWWDEEQEKAWRKQSRRKVMEAFEQAERKPKPNPNLLFSDVYQEMPAQL
RKQQESLARHLQTYGEHYPLDHFDK

Blast

To calculate the sequence alignments we used the blast and psiblast binaries from NCBI (version 2.2.26+) As the standard blast alignment hit the limit of 250 matches per alignment, that all were still seemed very significant (Evalue of < 1e-60) we increased the number of max target hits to 1900, till no further hits were made.

As can be seen in the figure to the right

Distibution of sequence similarity with the BCKDHA blast-query against the big80 database.

, the sequence alignments mainly have a similarity between 15% and 40%.