Question

D) Consider that during replication of the cell. the following mutations were generated within the gene sequence. Find the mutation (in bold Italics-underlined Specify the protein sequences for each mutant sequence. mutation type 1: This is a non-sense mutation because the codon does not code for an amino acid any more 5' -..AACTAATGCCGTAAGACGTATTTTGACTAAT..-3' (substitution of a C 7 A in codon 3) 3'- TTGATTACGGCAT ICTGCATAAAACTGATTA..-5 S mutation type 2: This is a missense mutation because the codon now codes for a different amino acid NACTMATGCCGTAGAAGTATTTTGACTAAT..-3! (substitution of Ain codon 4) . TTGATTACGGCATGCTICATAAAACTGATTA. .-5! 3

Answer 1

In case I which is a case of non-sense mutation a type of point mutation which makes no change in the amino acid sequence as we can see the amino acid formed in normal and mutated mRNA like the amino acids form before and after substitution is same without causing any change to the amino acid sequence.

In the second case which is a situation of missense mutation a type of point mutation results in a change in amino acid by substituting adenine in place of cytosine changing the amino acid from Aspartic acid to Glutamic acid after the substitution.

In the third case which is a silent mutation which does not result in a change in amino acid but the sequence is changed by substituting Adenine in place guanine but the resultant amino acid still remains the same so this shows no change in amino acid sequence so-called as silent mutation.

The fourth case is an example of a frameshift mutation in which cytosine is added in the third codon which changes the amino acid sequence completely after the addition.

2 Non-sense mutation AT6 cccТАА АСТАТТТТАСТЛА1 “ТАС 46CA1, стаса, CATAAAACT GATIA MRNA, AUGCCQUA A GAC GUAUUUUGALUA AD , Melhion Proline Stop 319 - 046 А14 (C41 A GAC GTA TIT 1GA C1A A1 ТАС (4C ATG CTC CAT AAA ACT «Att A S AVG CCG UACGAC GUA UUU UGA CUAA U me this proline Stop

z misseuse mutation w S AT ATG.CC.G IAC GAAGTAT117 GAC IAAT TAC GG CAIGCFT CAT A A AACTGATTA mRNA AUG CCG UAC GAA GUA UUUUGACUAAU ,5 | 5 Meth Broline Tyrosine Glutamic Valine Pheryl Stop 7 .. Acid Alanine V Normal SALG CCG TAC GAC GIA TIIT GACTAAT TAC GGC ATG GTG CATAAAA CIGALLA. LAUG cca UAC GAC GUAUUUU GACUAAN mRNA . Aspartia Aced

3 Silent Mutation ATG CCA TAC GACGIALLIGACTAAT TAC GGIATG CTG CATAAAACIGATLA. UUL mewn ANG CCAVALGACGUN OU OU SACURA U KNA Melluon Proline Nornal case Ş ATG COC TAC GAC G7A 1 TTT GACTAAT TAC GGT Ara CTG CATAAAA CIGATTA & Aua CCG UAC GAC GUA UUUUGACUARY Aua Poline A wit Boline nnar.

y frameshyt mutation Sят, ссс, ТАСС А. СТА ТЕтте АС 1 ААТ 1 TAC GGCAT, GCTGCA1AAAA CIGA11 A. AC CGA CGUA UU UU GACUA AU MRNA Methar Proline Tyrosine Arginine Arginine Iso leucine Theronine Aspargine U a leucine А14 сса ТАС 4 Ас 1А тітт<АС ТА А 1 з ТАс 44 C A14 ст, А1 АА АА столітА. AUG CCH VAC GAC GUA UUU UGA CUA A • roline Tyrosu Aspartic valene Phenyl Slop - Methioni *** Acid - Alamine