TABLE 1. Amino acid differences between mitochondrial and cytoplasmic aspartate aminotransferase in the putative fatty acid binding region of chicken heart mAsp-AT.

Throughout the binding site region as a whole, there are 15 hydrophobic amino acids in mAsp-AT compared with 10 in cAsp-AT. In the helices defining the RIGHT and LEFT boundaries of the binding site cleft, the 7 amino acids depicted in bold italic type have a difference in hydrophobicity or charge in cAsp-AT compared to their mAsp-AT counterpart. In 5 of these 7 instances, the change resulted in a relative decrease in hydrophobicity in cAsp-AT compared with mAsp-AT.

	mAsp-AT		cAsp-AT
Pos. #	AA	Type	AA	Type	Site
166	CYS	H	ARG	B
178	SER	P	GLU	A
180	ILE	H	ALA	H
198	VAL	H	THR	P	Buried		R I G H T
201	ARG	B	THR	P	Exposed
207	GLU	A	GLN	P	Exposed
212	VAL	H	MET	H	Buried
214	LYS	B	ARG	B	Exposed
216	ASN	P	PHE	H	Exposed
219	ALA	H	PRO	H	Buried
223	MET	H	SER	P	Buried
242	HIS	B	TYR	P	Exposed		L E F T
244	ILE	H	VAL	H	Buried
245	GLU	A	SER	P	Exposed
246	GLN	P	GLU	A	Exposed
248	ILE	H	PHE	H	Buried
250	VAL	H	LEU	H	Buried
252	LEU	H	CYS	H
256	TYR	H	PHE	H
257	ALA	H	SER	P
260	MET	H	PHE	H
264	GLY	H	ASN	P
269	ALA	H	ASN	P

Type: H = hydrophobic; P = uncharged polar; A = Acidic; B = basic