You want to identify where a peroxisome-targeting signal sequence is in a yeast

Question

You want to identify where a peroxisome-targeting signal sequence is in a yeast protein called thiolase. To do so, you create a set of hybrid proteins that contain different parts of the thiolase protein sequence fused to another protein, histidinol dehydrogenase (HDH). You express these hybrid proteins (a-e) in different strains instead of the normal HDH (wt). If the hybrid proteins are imported into the peroxisome, the HDH portion of the protein cannot function, and the yeast cells do not grow on a medium lacking histidine. Your results are shown on the right. Which of the proteins a-e localize to the cytoplasm? Which of the proteins a-e localize to the peroxisome? What range of amino acid positions in the thiolase protein contains the signal sequence that targets proteins to the peroxisome? 1-50 50-100 100-125 125-150 150-200 Please explain your conclusion for Part C.

Explanation / Answer

A. Wild type protein, c, d & e proteins localized in the cytoplasm. Due to this, there is functional HDH gene and grown in media that lack Histidine

B. a & b. Because they lach functional HDH gene and not grown in media that lack Histidine

C. 50-100

D. a & b both enter into peroxysomes. In a, all the sequence i.e 1-100 present. But In b, only 50-100 present. Even though it enter in to the peroxysomes. That menas the first 1-50 amino acids are not necessary for the transport of protein to the peroxysomes

Related Questions

Navigate

• Browse (All)
• Browse Y
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.