Mutational event to the frameshift mutant
Biology
Some amino acids are post-translationally removed from the C-terminal end of the b-lactamase enzyme from B. imaginarium (i.e. – after translation and release from the ribosome, a protease chews off a few amino acids). The purified wildtype enzyme is 327 amino acids in length and the sequence of its C-terminal amino acids is shown below aligned with the C-terminal amino acids found in a mutant strain of B. imaginarium, which contains of a frameshift mutation that abolishes processing if its C-terminus. This frameshift mutant was caused by insertion or deletion of a single nucleotide. Use this information to answer the questions below.
AA# 327
wild-type: Ser Asn Ala Lys Asp Trp
mutant: Ser Asn Ala Ile Arg Leu Asp Trp Gln Met Lys
A. What was the mutational event that gave rise to the frameshift mutant? Determine precisely where the single nucleotide insertion or deletion occurred in the b-lactamase coding sequences.
B. What is the length of the wildtype enzyme prior to processing (how many amino acids)?
C. Deduce, as far as possible, the actual sequence of the C-terminus of the wild-type enzyme prior to processing.
