After the addition of three glucose molecules to the completed oligosacharide pr
ID: 56480 • Letter: A
Question
After the addition of three glucose molecules to the completed oligosacharide precursur (Glc3Man9(GlcNAc)2), which of the following reactions most likely occurs?
The unfolded protein response
Folding and retention by lectin domain containing proteins
The recruitment of hnRNPs
Protein disulfide isomerase mediated oxidation
Glycosylation of a new protein which is/has entered the ER lumen catalyzed by oligosaccharyl transferase
The unfolded protein response
Folding and retention by lectin domain containing proteins
The recruitment of hnRNPs
Protein disulfide isomerase mediated oxidation
Glycosylation of a new protein which is/has entered the ER lumen catalyzed by oligosaccharyl transferase
Explanation / Answer
After the addition of three glucose molecules to the completed oligosacharide precursur (Glc3Man9(GlcNAc)2),
1. The glycosylation step take place to form a glycoprotein and for the formation of the glycoprotein the sugars are to be attached to the amide nitrogen of Asparagine of the nasent protein to form the N-linked Oligosaccharides . Asparagine can only accept the residues if it possess the linkage like Asn-x-Ser or Asn-x-Thr ,the X may be any amino acid residue and these N-linked Oligosaccharides are formed by the 3- mannose and 2-N-acetyl glycosamine residues.So this total process takes place at the ER lumen with the help of the enzyme Oligosaccharyl transferase.
2. After this process they enter the golgi complex for the modifications and
3. In the last step they undergo protein folding and help in stability of the glycoprotein.