A few amino acids arepost-translationally removed from the C-terminal end of theb-lactamase enzyme fromB. imaginarium (i.e. - after translation and releasefrom the ribosome, a protease chews off a few amino acids).The purified wildtype enzyme is 327 amino acids inlength and the sequence of its C-terminal amino acids is shownbelow aligned with the C-terminal amino acids found in a mutantstrain of B.imaginarium, which containsof a frameshift mutation that abolishes processingif its C-terminus. This frameshift mutant was caused by insertionor deletion of a single nucleotide. Usethis information to answer the questions below.
wild-type: Ser Asn Ala LysAsp Trp
mutant: Ser Asn Ala Ile Arg Leu Asp Trp Gln MetLys
A. What was the mutational event that gave rise to the frameshiftmutant? Determine precisely where the single nucleotide insertionor deletion occurred in the b-lactamase codingsequences.
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 theC-terminus of the wild-type enzyme prior to processing.
A few amino acids arepost-translationally removed from the C-terminal end of theb-lactamase enzyme fromB. imaginarium (i.e. - after translation and releasefrom the ribosome, a protease chews off a few amino acids).The purified wildtype enzyme is 327 amino acids inlength and the sequence of its C-terminal amino acids is shownbelow aligned with the C-terminal amino acids found in a mutantstrain of B.imaginarium, which containsof a frameshift mutation that abolishes processingif its C-terminus. This frameshift mutant was caused by insertionor deletion of a single nucleotide. Usethis information to answer the questions below.
wild-type: Ser Asn Ala LysAsp Trp
mutant: Ser Asn Ala Ile Arg Leu Asp Trp Gln MetLys
A. What was the mutational event that gave rise to the frameshiftmutant? Determine precisely where the single nucleotide insertionor deletion occurred in the b-lactamase codingsequences.
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 theC-terminus of the wild-type enzyme prior to processing.
