Consequences of mutations on protein sequence and function
the central dogma explains how information in DNA is convertedinto the sequence of amino acids in a protein
How do changes in DNA correlate with changes in the sequence of amino acids in a protein?
a. silent mutation:
a change in a base pair does not result in a change
in the sequence of amino acids in a protein
b. neutral mutation:
a change in a base pair results in an amino acid change
but the new amino acid has the same chemical properties as the old amino acid.
(ie hydrophobic to hydrophobic; acidic to acidic)
c. missense mutation:
a mutation results a change in an amino acid
where the new amino acids has a different property than the old amino acid.
The protein with the new primary structure may have reduced or no activity.
d. nonsense mutations:
a mutation results in a new stop translation condon formed before the naturally occuring one.
Translation is stopped prematurely and a shortened protein is made.
e. frameshift mutation:
a deletion or insertion of one base results in a change in the translational reading frame