L5: Yeast Expression System

Question 1

Upstream sequences in heterologous gene expression 
in eukaryotes

Answer 1

• Upstream activation sequence (UAS, enhancer), works with host transcription factors, may be inducible or constitutive
• TATA box for start of transcription
• Kozak sequence for translation initiation (AUG codon is an optimal context for start of translation)

Question 2

Downstream sequences

Answer 2

Polyadenylation site (adds ~500 A to increase stability)
Termination sequences