Table 1.

Amino acid residues that are conserved in the FGF family

Conserved residue	SA score	Conserved residue	SA score	Conserved residue	SA score
L23	0.0015	M76	0.0016	Y106	0.0033
Y24	0.2775	G80	0.0004	S108	0.0053
L32	0.0015	L82	0.0115	G122	0.0409
G38	0.0753	C92	0.0052	G127	0.0015
G42	0.0884	F94	0.0005	L138	0.0991
V63	0.0516	E96	0.3037	F139	0.0007
I65	0.0022	S100	0.9254	L140	0.2997
G67	0.0093	N101	0.4518	P141	0.2745
Y73	0.1729	Y103	0.1788

The conserved amino acid residues were identified by aligning the sequences of all 18 FGF family members by using three different multiple sequence alignment programs (22–24). The numbering of the amino acids corespond to their position in the FGF-2 sequence. All three of the sequence alignment programs resulted in identifying the identical set of conserved residues, although the alignment (not shown in the table) was quite different, especially at the N and the C termini. The normalized solvent-accessible surface areas (SA scores) of the conserved amino acids in the FGF-2 crystal structure are tabulated. Surface-accessible residues selected as described in Methods are shown in boldface type. These normalized solvent-accessible surface area values were computed by using coordinates of the FGF-2 crystal structure (Protein Data Bank ID: 1 fga) as described in Methods. Note that amino acids R22 and M142 were not included in the analysis, although they have been included in the site-directed mutagenesis studies (33). These amino acids correspond to the N- and the C-terminal regions of the crystal structures and hence did not provide reliable solvent-accessibility values.