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Quantum refinement of [FeFe] hydrogenase indicates a dithiomethylamine ligand.

Ryde, Ulf LU ; Greco, Claudio LU and De Gioia, Luca (2010) In Journal of the American Chemical Society 132(13). p.4512-4512
Abstract
The active site of the [FeFe] hydrogenases contains two Fe ions bound to one Cys ligand, three CO molecules, two CN(-) ions, and a dithiolate ligand. The nature of the last of these has been much discussed, and it has been suggested that it contains C, N, or O as the bridgehead atom. Most experimental studies indicate a N atom, whereas a recent density functional theory (DFT) study of a crystal structure indicated an O atom. Here, we performed quantum refinement on the same crystal structure with five different models of the dithiolate ligand X(CH(2)S(-))(2), with X = CH(2), NH(2)(+), NH (two conformations), or O; we found that structures with a N bridgehead atom actually provide the best fit to the raw crystallographic data. Quantum... (More)
The active site of the [FeFe] hydrogenases contains two Fe ions bound to one Cys ligand, three CO molecules, two CN(-) ions, and a dithiolate ligand. The nature of the last of these has been much discussed, and it has been suggested that it contains C, N, or O as the bridgehead atom. Most experimental studies indicate a N atom, whereas a recent density functional theory (DFT) study of a crystal structure indicated an O atom. Here, we performed quantum refinement on the same crystal structure with five different models of the dithiolate ligand X(CH(2)S(-))(2), with X = CH(2), NH(2)(+), NH (two conformations), or O; we found that structures with a N bridgehead atom actually provide the best fit to the raw crystallographic data. Quantum refinement is standard crystallographic refinement in which the molecular mechanics force field normally used to supplement the experimental raw data to give a more chemical structure is replaced by more accurate DFT calculations for the active site. Thereby, we obtain structures that are an ideal compromise between DFT and crystallography. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of the American Chemical Society
volume
132
issue
13
pages
4512 - 4512
publisher
The American Chemical Society
external identifiers
  • wos:000276553600005
  • pmid:20230002
  • scopus:77950818400
ISSN
1520-5126
DOI
10.1021/ja909194f
language
English
LU publication?
yes
id
1311e108-c3b7-472e-899d-516a732c15cd (old id 1582149)
date added to LUP
2010-04-21 12:17:11
date last changed
2018-11-18 04:09:38
@article{1311e108-c3b7-472e-899d-516a732c15cd,
  abstract     = {The active site of the [FeFe] hydrogenases contains two Fe ions bound to one Cys ligand, three CO molecules, two CN(-) ions, and a dithiolate ligand. The nature of the last of these has been much discussed, and it has been suggested that it contains C, N, or O as the bridgehead atom. Most experimental studies indicate a N atom, whereas a recent density functional theory (DFT) study of a crystal structure indicated an O atom. Here, we performed quantum refinement on the same crystal structure with five different models of the dithiolate ligand X(CH(2)S(-))(2), with X = CH(2), NH(2)(+), NH (two conformations), or O; we found that structures with a N bridgehead atom actually provide the best fit to the raw crystallographic data. Quantum refinement is standard crystallographic refinement in which the molecular mechanics force field normally used to supplement the experimental raw data to give a more chemical structure is replaced by more accurate DFT calculations for the active site. Thereby, we obtain structures that are an ideal compromise between DFT and crystallography.},
  author       = {Ryde, Ulf and Greco, Claudio and De Gioia, Luca},
  issn         = {1520-5126},
  language     = {eng},
  number       = {13},
  pages        = {4512--4512},
  publisher    = {The American Chemical Society},
  series       = {Journal of the American Chemical Society},
  title        = {Quantum refinement of [FeFe] hydrogenase indicates a dithiomethylamine ligand.},
  url          = {http://dx.doi.org/10.1021/ja909194f},
  volume       = {132},
  year         = {2010},
}