The following base sequence is found for a mRNA fragment from wild-type E. coli:
5'- UAUCAGUAGAUAAUGUAACC-3'
1. Assuming that this sequence corresponds to the middle of a gene's coding region, give the amino acid sequence of the protein you would expect the fragment to encode.
Write your answer in the (lower case) 3 letter amino acid code such as leu, trp, phe, etc, and place a comma after each amino acid and no spaces or periods: example: met,phe,trp,arg,asp

In the question, a mRNA (messenger Ribonucleic acid) sequence is given in the 5'→3' orientation.
The Ribosome is responsible for translating the ribo-nucleotide code (mRNA) into the amino acid code (polypeptide).
The Ribosome reads the ribo-nucleotide codes in form of triplets. This means that three ribo-nucleotides code for a single amino acid. Each such triplet is called a Codon. Hence, each codon codes for a single amino acid.
The specific amino acid that a codon is specific for, is given by the Genetic Code table.
Dividing the given sequence into codons and representing the amino acids encoded below:

5'- UAU CAG UAG AUA AUG UAA CC-3'

tyr gln stop

The above codon frame is not possible because UAG is a stop codon, where translation ends and that happens only at the end of the mRNA at not in between. The question states that the sequence is taken from the middle of the gene's coding region.
So changing the frame of the codons,

5'- UA UCA GUA GAU AAU GUA ACC-3'

↓ ser val asp asn val thr

(leu/ile/val)

In the first codon the first nucleotide is missing, so the exact amino acid encoded cannot be determined. However, as the rest two nucleotides are given, it can be predicted that the amino acid can be:

(leu/ile/val), ser, val, asp, asn, val, thr