TABLE 2.

Different conformations in MyoD versus A114N mutant proteins inferred from Gal fusion experiments^a

Gal4 fusion constructb	G5-LacZ activityc
Control	1
(1–318)MyoD	20
(1–318)A114N	200
(1–75)MyoD	2,000
(1–101)MyoD	600
(1–127)MyoD	1
(1–127)A114N	1
(1–161)MyoD	0.3
(1–161)A114N	0.3

^aNIH 3T3 cells were transfected with 1.5 μg of G5-E1b-LacZ reporter plasmid and 1.5 μg of Gal4 fusion constructs on 60-mm-diameter duplicate plates. 

^bControl, activity of the reporter plus empty fusion vector; (1–75)MyoD is a Gal4 fusion construct carrying the 75 amino-terminal residues of MyoD including the previously defined N-terminal activation domain (aa 1 to 53); (1–101), (1–127), and (1–161) indicate proteins that are truncated at the end of the Cys- and His-rich domain, the junction of the basic region and helix 1, and the end of helix 2, respectively; (1–318) indicates full-length proteins. 

^cThe results were derived from 5 to 10 independent experiments and are expressed as the ratio to the activity of the control.