Table 1.

Conformational changes in cyt b and ISP subunits of the bc₁ complex upon inhibitor binding

Inhibitor bound structure	Inhibitor class	[2Fe2S]* anomalous peak	rmsd for Cα,†Å		Displacement relative to the native,‡ Å			Changes in binding of ISP to cyt b
			Cyt b (3–379)	Qo site§ 32 residues	bI146Cα	bP270Cα	bS151Cα	CA,¶ (Å2)	SC‖
Native**		0.52	—	—	0.0	0.0	0.0	—	0.55
Azoxystrobin	Pm	0.36	0.26	0.72	−0.76	1.81	−0.71	−86	0.39
Myxothiazol	Pm	0.46	0.26	0.81	−0.57	1.66	−0.71	−69	0.38
MOAS	Pm	0.23	0.23	0.59	−0.35	1.62	−0.42	−78	0.39
Famoxadone	Pf	1.02	0.33	0.91	+0.87	1.96	+0.58	65	0.60
UHDBT	Pf	0.96	0.40	1.11	+1.73	0.72	+0.60	129	0.60
Stigmatellin	Pf	1.20	0.33	1.32	+1.61	1.58	+0.96	92	0.60
JG144††	Pf	1.17	0.28	0.81	+1.06	1.86	+0.52	79	0.59
NQNO	PN	0.83	0.33	0.59	—	—	—	56	0.61
Stig-yeast‡‡	Pf	—	—	—	—	—	—	—	—
Antimycin A§§	N	0.51	0.31	0.59	+0.34	0.24	−0.15	—	—

*Normalized anomalous difference Fourier peaks for the Fe atoms in the ISP subunit (15).

^†rmsds in Å between cyt b subunits of inhibitor-bound and native bc₁ complex.

^‡Distance between residues either in the same subunit or in different subunits. Superscript letter on the left denotes subunit; subscript on the right is for atom type.

^§Residues included in the calculation are 141–160, 167–170, and 263–270 of the cyt b subunit.

^¶CA between ISP and cyt b. The CA is calculated by using the ISP extrinsic domain only (71–196). The native (apo) protein has a CA of 356 Ų.

^‖Surface complementarity (16).

**Native coordinates are from Protein Data Bank ID code 1NTM (17).

^††The chemical structure of JG144 is S-3-anilino-5-methyl-5-(4,6-difluorophenyl)-1,3-oxazolidine-2,4-dione.

^‡‡Obtained from ref. 18.

^§§Obtained from ref. 17.