Genetic variants in the putidaredoxin-cytochrome P-450CAM electron-transfer complex: identification of the residue responsible for redox-state-dependent conformers

Biochemistry ◽  
1992 ◽  
Vol 31 (46) ◽  
pp. 11383-11389 ◽  
Author(s):  
Matthew D. Davies ◽  
Stephen G. Sligar
2005 ◽  
Vol 99 (2) ◽  
pp. 600-605 ◽  
Author(s):  
Laura Santagostini ◽  
Michele Gullotti ◽  
James T. Hazzard ◽  
Silvana Maritano ◽  
Gordon Tollin ◽  
...  

2004 ◽  
Vol 71 ◽  
pp. 1-14
Author(s):  
David Leys ◽  
Jaswir Basran ◽  
François Talfournier ◽  
Kamaldeep K. Chohan ◽  
Andrew W. Munro ◽  
...  

TMADH (trimethylamine dehydrogenase) is a complex iron-sulphur flavoprotein that forms a soluble electron-transfer complex with ETF (electron-transferring flavoprotein). The mechanism of electron transfer between TMADH and ETF has been studied using stopped-flow kinetic and mutagenesis methods, and more recently by X-ray crystallography. Potentiometric methods have also been used to identify key residues involved in the stabilization of the flavin radical semiquinone species in ETF. These studies have demonstrated a key role for 'conformational sampling' in the electron-transfer complex, facilitated by two-site contact of ETF with TMADH. Exploration of three-dimensional space in the complex allows the FAD of ETF to find conformations compatible with enhanced electronic coupling with the 4Fe-4S centre of TMADH. This mechanism of electron transfer provides for a more robust and accessible design principle for interprotein electron transfer compared with simpler models that invoke the collision of redox partners followed by electron transfer. The structure of the TMADH-ETF complex confirms the role of key residues in electron transfer and molecular assembly, originally suggested from detailed kinetic studies in wild-type and mutant complexes, and from molecular modelling.


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