Table 2. Structural attributes of predictive motif elements.

Site no.	Max no.	Site	Motif?	Max	Structural explanation	Myc	Mismatch	Site no.	Mad	Site no.
1	24	B1	Y	K	Contacts DNA (A7'); beginning of Basic region	K		355	S	57
2	25	B2	Y	R	Contacts phosphate backbone	R		356	R	58
3	26	B3	Y	A		R	2	357	S	59
4	27	B4		H		T		358	T	60
5	28	B5	Y	H	Contacts DNA (G3'); bHLH group designation	H	1	359	H	61
6	29	B6	Y	N	Contacts phosphate backbone	N	4	360	N	62
7	30	B7		A		V		361	E	63
8	31	B8	Y	L		L	1	362	M	64
9	32	B9	Y	E	Contact with DNA (C3 and A2)	E		363	E	65
10	33	B10	Y	R	Contacts phosphate backbone	R		364	K	66
11	34	B11		K		Q		365	N	67
12	35	B12	Y	R	Contacts phosphate backbone	R	2	366	R	68
13	36	B13	Y	R	Contacts DNA and phosphate backbone	R	3	367	R	69
14	37	H1		D		N		368	A	70
15	38	H2	Y	H		E		369	H	71
16	39	H3	Y	I	Side chain packs against F43; buried site	L	2	370	L	72
17	40	H4	Y	K		K		371	R	73
18	41	H5		D		R		372	L	74
19	42	H6		S		S		373	C	75
20	43	H7	Y	F	Many Van der Waals contacts with H2 side chains; buried site	F		374	L	76
21	44	H8		H		F		375	E	77
22	45	H9		S		A		376	K	78
23	46	H10	Y	L	Packs against 63 and 67; buried site	L		377	L	79
24	47	H11	Y	R		R		378	K	80
25	48	H12	Y	D		D		379	G	81
26	49	H13		S		Q		380	L	82
27	50	H14		V	Packs against 70	1		381	V	83
28	51	H15	Y	P	End of Helix 1; P residue turns strand; packs against 70; buried site	P	2	382	P	84

Explanations are based on Ferre-D'Amare et al. (21) for Max. The numbering schemes are based on the human sequences for the Max, Myc, and Mad proteins.