Final answer:
A 'missense mutation' resulted in the substitution of isoleucine for valine in the protein sequence, changing the normally encoded amino acid to a different one.
Step-by-step explanation:
The mutation in the protein sequence described is a missense mutation. In this particular case, the normal amino acid sequence 'tryp-gln-val-ser-leu' has been altered to 'tryp-gln-ile-ser-leu'. The valine (val) has been replaced by isoleucine (ile).
Missense mutations occur when a single nucleotide change in a DNA sequence leads to the substitution of one amino acid for another in the protein produced.
An example of the impact of such a mutation is seen in sickle cell anemia, where the amino acid glutamic acid is replaced by valine, leading to dramatic changes in the shape and function of red blood cells.