|
type |
Journal Article |
authors |
Pares, S.; Cohen-Addad, C.; Sieker, L.; Neuburger, M.; Douce, R. |
title |
X-ray structure determination at 2.6-A resolution of a lipoate- containing protein: the H-protein of the glycine decarboxylase complex from pea leaves |
journal |
Proc Natl Acad Sci U S A |
Activity |
1.4.4.2 |
ui |
94255425 |
year |
(1994) |
volume |
91 |
number |
11 |
pages |
4850-3. |
| |
keywords |
Amino Acid Oxidoreductases/*chemistry |
abstract |
H-protein, a lipoic acid-containing protein of the glycine decarboxylase (EC 1.4.4.2) complex from pea (Pisum sativum) was crystallized from ammonium sulfate solution at pH 5.2 in space group P3(1)21. The x-ray crystal structure was determined to 2.6-A resolution by multiple isomorphous replacement techniques. The structure was refined to an R value of 23% for reflections between 15- and 2.6-A resolution (F > 2 sigma), including the lipoate moiety and 50 water molecules, for the two protein molecules of the asymmetric unit. The 131-amino acid residues form seven beta-strands arranged into two antiparallel beta-sheets forming a "sandwich" structure. One alpha- helix is observed at the C-terminal end. The lipoate cofactor attached to Lys-63 is located in the loop of a hairpin configuration. The lipoate moiety points toward the residues His-34 and Asp-128 and is situated at the surface of the H-protein. This allows the flexibility of the lipoate arm. This is the first x-ray determination of a lipoic acid-containing protein, and the present results are in agreement with previous theoretical predictions and NMR studies of the catalytic domains of lipoic acid- and biotin-containing proteins. |
last changed |
2002/11/04 17:41 |
|