Table 2. Geometry of the heme groups and their environment in mouse, human, DMouse and GPig Hbs.

	Mouse met		DMouse aquo-met R		DMouse deoxy T		GPig met R2		Human oxy R		Human carboxy R		Human deoxy T		Human met R2
	α1	β1	α1	β1	α1	β1	α1	β1	α1	β1	α1	β1	α1	β1	α1	β1
Fe–His (F8) NE2 (Å)	2.10	1.82	2.24	2.26	2.50	2.56	1.98	1.99	1.94	2.07	1.93	2.16	2.15	2.15	2.35	2.47
Fe–His (E7) NE2 (Å)	4.19	3.93	4.17	4.14	4.23	4.05	4.23	4.31	4.31	4.19	4.47	4.19	4.50	4.14	5.19	4.24
Fe–Val (E11) CG2 (Å)	5.70	4.25	4.99	4.72	4.85	4.40	4.84	4.77	4.79	4.66	5.06	5.16	5.23	4.12	4.98	4.83
Fe–Phe (CD1) CZ (Å)	5.15	6.05	5.41	5.74	5.18	5.56	5.15	5.40	5.51	5.66	5.52	5.66	5.98	6.74	5.34	5.18
His (E7) NE2–Fe–His (F8) NE2 (°)	149.3	112.8	154.9	151.2	131.2	135.9	153.9	148.8	147.9	137.8	146.6	140.0	159.8	149.4	122.6	134.2
Fe–plane distance† (Å)	0.16	0.04	0.13	0.14	0.02	0.1	0.11	0.14	0.15	0.06	0.01	0.05	0.54	0.17	0.19	0.5

^†The plane is defined as the porphyrin ring atoms excluding the side chains (methyl, ethyl and acid groups) and the Fe atom.