week%209%20challenge%20prob

week%209%20challenge%20prob - 1.What are the possible...

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The bacterial ligase enzyme can be isolated and its amino acid sequence determined. Shown below are the wild type sequence for part of the polypeptide chain and the same part from a double mutant formed from two frameshift mutants, one + and one D in the same gene copy. Wild type Tyr Thr Tyr Leu Leu Ser Arg Ala Double mutant Tyr Thr Phe Cys Cys His Gly Ala These 5 amino acids form the only region of difference between them; everything at the N-terminal end and everything at the C-terminal end is unchanged. It will be helpful to write down all the possible codons as you go through the questions.
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Unformatted text preview: 1.What are the possible codons for the Tyr residue that is changed in the double mutant? 2.Does any frameshift single nucleotide addition or deletion result in changing that Tyr residue to Phe? 3.How does that result in changing also the Leu residue to Cys and Ser to His? 4.In a gene copy with the original frameshift mutation (Tyr to Phe), what 2 nd mutant could give rise to Gly at the 7 th residue (ie after His)? 5.Would your choice of 2 nd mutant lead to the normal Ala residue next in line?...
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This note was uploaded on 07/08/2009 for the course LIFESCI ls 4 taught by Professor Merriam during the Winter '08 term at UCLA.

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