Practice question

Question

You are interested in a particular enzyme that is expressed in various human tissues. You have isolated the protein from the brain, liver and kidneys. After a lot of experimentation you determine that the liver protein has three domains A, B and C occurring in sequential order. Domain B is the catalytic domain and the other two have regulatory function. The kidney protein has only domains A and B in that order and the brain protein has domains B and C. You then proceed to determine the primary structure of the proteins using chemical methods and find that the amino acid sequence of the three domains are completely identical regardless of the source from which they were isolated. You then ask the question whether the three different proteins have all originated from the same gene by means of alternative splicing, or they could be products of different genes. Having the experimentally determined protein sequences and knowing the sequence of the human genome, which one of the following bioinformatic method you will use to answer the question above.