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