In:
Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 95, No. 14 ( 1998-07-07), p. 8026-8033
Abstract:
We have analyzed crystal structures of cytochrome bc 1 complexes with electron transfer inhibitors bound to the ubiquinone binding pockets Q i and/or Q o in the cytochrome b subunit. The presence or absence of the Q i inhibitor antimycin A did not affect the binding of the Q o inhibitors. Different subtypes of Q o inhibitors had dramatically different effects on the mobility of the extramembrane domain of the iron–sulfur protein (ISP): Binding of 5-undecyl-6-hydroxy-4,7-dioxobenzothiazol and stigmatellin (subtype Q o –II and Q o –III, respectively) led to a fixation of the ISP domain on the surface of cytochrome b , whereas binding of myxothiazol and methoxyacrylate-stilbene (subtype Q o –I) favored release of this domain. The native structure has an empty Q o pocket and is intermediate between these extremes. On the basis of these observations we propose a model of quinone oxidation in the bc 1 complex, which incorporates fixed and loose states of the ISP as features important for electron transfer and, possibly, also proton transport.
Type of Medium:
Online Resource
ISSN:
0027-8424
,
1091-6490
DOI:
10.1073/pnas.95.14.8026
Language:
English
Publisher:
Proceedings of the National Academy of Sciences
Publication Date:
1998
detail.hit.zdb_id:
209104-5
detail.hit.zdb_id:
1461794-8
SSG:
11
SSG:
12
