BIOINORGANIC CHEMISTRY A Short Course Second Edition

406 IRON-CONTAINING PROTEINS AND ENZYMES

Figure 7.30

Comparison of cytochrome bc

structures: (A) PDB: 1PP9 with inhibitor stigmatellin; and (B) PDB: 1PPJ with inhibitors 1

stigmatellin and antimycin A. Visualized using The PyMOL Molecular Graphics System and ChemDraw Ultra, version 10.0. (Printed w

ith

permission of Delano Scientifi

c, LLC and CambridgeSoft Corporation.) (See color plate)

heme b

L

monomer B

heme c

1

monomer

Å

[2Fe-2S]

B

stigmatellin

heme b

L

monomer

Å

heme b

H

monomer

Å

antimycin

antimycin

heme b

H

stigmatellinmonomer B

[2Fe-2S]monomer

Å

heme c

1

B monomer B

PDB: 1PPJ cytochrome bc

with inhibitor stigmatellin and antibiotic 1

antimycin.Note [2Fe-2S] centers interact with hemes in the other monomer.

heme c

1

monomer Å

[2Fe-2S]monomer B

stigmatellin

heme b

L

monomer Å

heme b

H

monomer Å

heme c

1

monomer

B

[2Fe-2S]monomer Å

stigmatellin

heme

31.04

15.99

20.56

20.55

30.58

26.00

30.66

30.6

25.94 20.63

26.04

20.63

bL

monomer

heme b

H

monomer B

PDB: 1PP9 cytochrome bc

with inhibitor stigmatellin 1

All distances in angstroms.

Note [2Fe-2S] centers interact with hemes in the othermonomer.

A

Q

sitei

Q

siteo