This alters codon 4 from AGC (cysteine, a sulfur-containing amino acid) to ATC (isoleucine, a hydrophobic amino acid). This is a big change in the chemical nature of the amino acid coded and will probably have a large affect on protein structure and function.
Work Step by Step
To understand, just translate the new protein, especially from the position of the frameshift. Change the T's to U's and then use Table 15.1. Consider the large chemical shift from Cys to Ile and its probable effect on the protein.