کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1942606 | 1052619 | 2011 | 7 صفحه PDF | دانلود رایگان |

The cytochrome bc1 complex is a key component in several respiratory pathways. One of the characteristics of the eukaryotic complex is the presence of a small acidic subunit, which is thought to guide the interaction of the complex with its electron acceptor and facilitate electron transfer. Paracoccus denitrificans represents the only example of a prokaryotic organism in which a highly acidic domain is covalently fused to the cytochrome c1 subunit. In this work, a deletion variant lacking this acidic domain has been produced and purified by affinity chromatography. The complex is fully intact as shown by its X-ray structure, and is a dimer (Kleinschroth et al., subm.) compared to the tetrameric (dimer-of-dimer) state of the wild-type. The variant complex is studied by steady-state kinetics and flash photolysis, showing wild type turnover and a virtually identical interaction with its substrate cytochrome c552.
► The role of a unique acidic domain in the c1 subunit of complex III is addressed.
► In a deletion variant, neither kCAT nor KM are changed.
► Laser flash photolysis indicates same substrate interaction in the variant complex.
Journal: Biochimica et Biophysica Acta (BBA) - Bioenergetics - Volume 1807, Issue 11, November 2011, Pages 1383–1389