18, (3 pts) GALT exists as a homodimer. Explain what this means for the protein

Question

18, (3 pts) GALT exists as a homodimer. Explain what this means for the protein regarding its structure. Include the level of structure (i.e., primary, secondary, tertiary, quaternary structure) and the types of subunits it has, if any. 19. (3 pts) The mutated amino acid is close to the active site (i.e., where the enzyme binds to and catalyzes the reaction) and close to the dimerization site. Name three different ways that the mutation could interfere with GALT activity. 20. (2 pts) Looking at the role of GALT in galactose metabolism, hypothesize why humans with a GALT mutation often leads to infant mortality. Include in your answer how it relates to lactose metabolism.

Explanation / Answer

18. Gal-1-P uridyl transferase is an enzyme involved in th Galactose metabolism. It essentially occur as the homodimer. Active site of GALT at which the hexose bind is formed between the dimeric subunits.

19. Mutation in the GALT near its active site either dissociate the dimer loosing the active site of the enzyme which can't catalize transferase activity. Generally mutation occur in Leu4, Phe75, Asn77, Asp78, Phe79, and Val108 residues.

20. GALT is main enzyme in Glactose metabolism. The deficiency of GALT is also termed as Glactosemia. In this condition patient are unable to metabolose Galactose and since in infants Galactose from lactose is a main energy source the mutation will result in death of infant.

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

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