|
type |
Journal Article |
authors |
Lepore, B.W.; Ruzicka, F.J.; Frey, P. A.; Ringe, D. |
title |
The x-ray crystal structure of lysine-2,3-aminomutase from Clostridium subterminale |
journal |
Proc Natl Acad Sci U S A |
Activity |
5.4.3.2 |
Family |
5.4.3.2 |
PLP Fold Type |
7 |
sel |
selected |
ui |
16166264 |
year |
(2005) |
volume |
102 |
number |
39 |
pages |
13819-24 |
| |
abstract |
The x-ray crystal structure of the pyridoxal-5'-phosphate (PLP), S-adenosyl-L-methionine (SAM), and [4Fe-4S]-dependent lysine-2,3-aminomutase (LAM) of Clostridium subterminale has been solved to 2.1-A resolution by single-wavelength anomalous dispersion methods on a L-selenomethionine-substituted complex of LAM with [4Fe-4S](2+), PLP, SAM, and L-alpha-lysine, a very close analog of the active Michaelis complex. The unit cell contains a dimer of hydrogen-bonded, domain-swapped dimers, the subunits of which adopt a fold that contains all three cofactors in a central channel defined by six beta/alpha structural units. Zinc coordination links the domain-swapped dimers. In each subunit, the solvent face of the channel is occluded by an N-terminal helical domain, with the opposite end of the channel packed against the domain-swapped subunit. Hydrogen-bonded ionic contacts hold the external aldimine of PLP and L-alpha-lysine in position for abstraction of the 3-pro-R hydrogen of lysine by C5' of SAM. The structure of the SAM/[4Fe-4S] complex confirms and extends conclusions from spectroscopic studies of LAM and shows selenium in Se-adenosyl-L-selenomethionine poised to ligate the unique iron in the [4Fe-4S] cluster upon electron transfer and radical formation. The chain fold in the central domain is in part analogous to other radical-SAM enzymes. |
last changed |
2007/09/14 20:19 |
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