Purification, characterization, and cloning of trimethylamine dehydrogenase fromMethylophaga sp. strain SK1

2006 ◽  
Vol 11 (4) ◽  
pp. 337-343 ◽  
Author(s):  
Hee Gon Kim ◽  
Yan Kim ◽  
Heon Man Lim ◽  
Hyun-Jae Shin ◽  
Si Wouk Kim
Keyword(s):  
Trimethylamine Dehydrogenase

Flavin radicals, conformational sampling and robust design principles in interprotein electron transfer: the trimethylamine dehydrogenase-electron-transferring flavoprotein complex

2004 ◽  
Vol 71 ◽  
pp. 1-14
Author(s):  
David Leys ◽  
Jaswir Basran ◽  
François Talfournier ◽  
Kamaldeep K. Chohan ◽  
Andrew W. Munro ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Kinetic Studies ◽  
Molecular Assembly ◽  
Conformational Sampling ◽  
Trimethylamine Dehydrogenase ◽  
Key Residues ◽  
Electron Transferring Flavoprotein ◽  
Electron Transfer Complex

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.

scholarly journals Molecular structure of trimethylamine dehydrogenase from the bacterium W3A1 at 6.0-A resolution.

1984 ◽  
Vol 259 (23) ◽  
pp. 14458-14462 ◽  
Author(s):  
L W Lim ◽  
N Shamala ◽  
F S Mathews ◽  
D J Steenkamp
Keyword(s):  
Molecular Structure ◽  
Trimethylamine Dehydrogenase

scholarly journals Identification of ADP in the iron-sulfur flavoprotein trimethylamine dehydrogenase.

1988 ◽  
Vol 263 (7) ◽  
pp. 3075-3078
Author(s):  
L W Lim ◽  
F S Mathews ◽  
D J Steenkamp
Keyword(s):  
Trimethylamine Dehydrogenase ◽  
Iron Sulfur

scholarly journals Flavinylation in wild-type trimethylamine dehydrogenase and differentially charged mutant enzymes: a study of the protein environment around the N1 of the flavin isoalloxazine

1996 ◽  
Vol 317 (1) ◽  
pp. 267-272 ◽  
Author(s):  
Martin MEWIES ◽  
Leonard C. PACKMAN ◽  
F. Scott MATHEWS ◽  
Nigel S. SCRUTTON
Keyword(s):  
Escherichia Coli ◽  
Wild Type ◽  
Post Translational Modification ◽  
Mutant Proteins ◽  
Trimethylamine Dehydrogenase ◽  
Guanidino Group ◽  
Protein Environment ◽  
Mutagenic Changes ◽  
Positively Charged ◽  
Significant Mass

In wild-type trimethylamine dehydrogenase, residue Arg-222 is positioned close to the isoalloxazine N1/C2 positions of the 6S-cysteinyl FMN. The positively charged guanidino group of Arg-222 is thought to stabilize negative charge as it develops at the N1 position of the flavin during flavinylation of the enzyme. Three mutant trimethylamine dehydrogenases were constructed to alter the nature of the charge at residue 222. The amount of active flavinylated enzyme produced in Escherichia coli is reduced when Arg-222 is replaced by lysine (mutant R222K). Removal or reversal of the charge at residue 222 (mutants R222V and R222E, respectively) leads to the production of inactive enzymes that are totally devoid of flavin. A comparison of the CD spectra for the wild-type and mutant enzymes revealed no major structural change following mutagenesis. Like the wild-type protein, each mutant enzyme contained stoichiometric amounts of the 4Fe-4S cluster and ADP. Electrospray MS also indicated that the native and recombinant wild-type enzymes were isolated as a mixture of deflavo and holo enzyme, but that each of the mutant enzymes have masses expected for deflavo trimethylamine dehydrogenase. The MS data indicate that the lack of assembly of the mutant proteins with FMN is not due to detectable levels of post-translational modification of significant mass. The experiments reported here indicate that simple mutagenic changes in the FMN-binding site can reduce the proportion of flavinylated enzyme isolated from Escherichia coli and that positive charge is required at residue 222 if flavinylation is to proceed.

Electron transfer in trimethylamine dehydrogenase and electrontransferring flavoprotein

1999 ◽  
Vol 27 (2) ◽  
pp. 196-201 ◽  
Author(s):  
N. S. Scrutton ◽  
J. Basran ◽  
E. K. Wilson ◽  
K. K. Chohan ◽  
M.-H. Jang ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Trimethylamine Dehydrogenase
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