Question

You have carried out a two-hybrid screen with your favorite gene (which codes for your favorite protein YFP) and identified a gene that codes for a protein we’ll call “A.” YFP is only 90 amino acids long. You wish to identify which part of YFP binds to A. You construct three deletion alleles of YFP that are fused Gal4 binding domain, one contains the N-terminal 30 amino acids of YFP (1-30), one the middle 30 amino acids (31-60) and one the C-teminal 30 amino acids of YFP (61-90). You obtain the data in the figure below.

Expression of 2-hybrid reporter? Gal4 BD Y 1-30 Gal4 AD No Gal4 BD F 31-60 A Gal4 AD No Gal4 BD P 61-90 A Gal4 AD Yes

Based on this data, what is the minimum region of YFP that is required to bind to protein A?

A. amino acids 1-30

B. amino acids 31-60

C. amino acids 61-90

D. amino acids 1-60

E. amino acids 31-90

F. amino acids 1-30 and 61-90

G. amino acids 1-90

Answer 1

Correct answer is option C -  amino acids 61-90

Explanation: YEP protein which contain amino acids 61-90 binds with A protein and and expression of 2 hybrid reporter results. When YEP contain either 1-30 amino acids or 31-60 amino acids, no expression occurs. It indicates that amino acids 61-90 is responsible for binding with the protein A. So correct answer is option C