| Autor: |
Frauke Baymann, Barbara Schoepp-Cothenet, Simon Duval, Marianne Guiral, Myriam Brugna, Carole Baffert, Michael J. Russell, Wolfgang Nitschke |
| Jazyk: |
angličtina |
| Rok vydání: |
2018 |
| Předmět: |
|
| Zdroj: |
Frontiers in Microbiology, Vol 9 (2018) |
| Druh dokumentu: |
article |
| ISSN: |
1664-302X |
| DOI: |
10.3389/fmicb.2018.01357 |
| Popis: |
Electron bifurcation is here described as a special case of the continuum of electron transfer reactions accessible to two-electron redox compounds with redox cooperativity. We argue that electron bifurcation is foremost an electrochemical phenomenon based on (a) strongly inverted redox potentials of the individual redox transitions, (b) a high endergonicity of the first redox transition, and (c) an escapement-type mechanism rendering completion of the first electron transfer contingent on occurrence of the second one. This mechanism is proposed to govern both the traditional quinone-based and the newly discovered flavin-based versions of electron bifurcation. Conserved and variable aspects of the spatial arrangement of electron transfer partners in flavoenzymes are assayed by comparing the presently available 3D structures. A wide sample of flavoenzymes is analyzed with respect to conserved structural modules and three major structural groups are identified which serve as basic frames for the evolutionary construction of a plethora of flavin-containing redox enzymes. We argue that flavin-based and other types of electron bifurcation are of primordial importance to free energy conversion, the quintessential foundation of life, and discuss a plausible evolutionary ancestry of the mechanism. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
|
