The Q-cycle tunes electron transfer chains using menaquinone
نویسندگان
چکیده
منابع مشابه
A Q-cycle mechanism for the cyclic electron-transfer chain of Rhodopseudomonas sphaeroides.
Over the past few years, work from a number of laboratories has shown that the ubiquinol :cytochrome c, (QH, :cyt. c,) oxidoreductase of the cyclic photosynthetic electron-transport chain of R hodopseudomonas sphaeroides is essentially similar to the mitochondria1 complex 111. Scheme 1 summarizes our present knowledge of the thermodynamics, kinetics and stoichiometry of the components of the ch...
متن کاملModular origins of biological electron transfer chains.
Oxidoreductases catalyze electron transfer reactions that ultimately provide the energy for life. A limited set of ancestral protein-metal modules are presumably the building blocks that evolved into this diverse protein family. However, the identity of these modules and their path to modern oxidoreductases is unknown. Using a comparative structural analysis approach, we identify a set of funda...
متن کاملFixing the Q cycle.
Mitchell's key insight that all bioenergetic membranes run on the conversion of redox energy into transmembrane electrical and proton gradients took the form 30 years ago of a working model of the Q cycle of cytochrome bc1, which operates reversibly on coupled electron and proton transfers of quinone at two binding sites on opposite membrane faces. His remarkable model still stands today, but h...
متن کاملBiosynthesis of Menaquinone (Vitamin K2) and Ubiquinone (Coenzyme Q).
Escherichia coli and Salmonella contain the naphthoquinones menaquinone (MK; vitamin K2) and demethylmenaquinone and the benzoquinone ubiquinone (coenzyme Q; Q). Both quinones are derived from the shikimate pathway, which has been called a "metabolic tree with many branches." There are two different pathways for the biosynthesis of the naphthoquinones. The vast majority of prokaryotes, includin...
متن کاملHeme and menaquinone induced electron transport in lactic acid bacteria
BACKGROUND For some lactic acid bacteria higher biomass production as a result of aerobic respiration has been reported upon supplementation with heme and menaquinone. In this report, we have studied a large number of species among lactic acid bacteria for the existence of this trait. RESULTS Heme- (and menaquinone) stimulated aerobic growth was observed for several species and genera of lact...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Biochimica et Biophysica Acta (BBA) - Bioenergetics
سال: 2014
ISSN: 0005-2728
DOI: 10.1016/j.bbabio.2014.05.329