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PDBsum entry 3a7u
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References listed in PDB file
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Key reference
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Title
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Global conformational change associated with the two-Step reaction catalyzed by escherichia coli lipoate-Protein ligase a.
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Authors
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K.Fujiwara,
N.Maita,
H.Hosaka,
K.Okamura-Ikeda,
A.Nakagawa,
H.Taniguchi.
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Ref.
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J Biol Chem, 2010,
285,
9971-9980.
[DOI no: ]
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PubMed id
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Abstract
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Lipoate-protein ligase A (LplA) catalyzes the attachment of lipoic acid to
lipoate-dependent enzymes by a two-step reaction: first the lipoate adenylation
reaction and, second, the lipoate transfer reaction. We previously determined
the crystal structure of Escherichia coli LplA in its unliganded form and a
binary complex with lipoic acid (Fujiwara, K., Toma, S., Okamura-Ikeda, K.,
Motokawa, Y., Nakagawa, A., and Taniguchi, H. (2005) J Biol. Chem. 280,
33645-33651). Here, we report two new LplA structures, LplA.lipoyl-5'-AMP and
LplA.octyl-5'-AMP.apoH-protein complexes, which represent the post-lipoate
adenylation intermediate state and the pre-lipoate transfer intermediate state,
respectively. These structures demonstrate three large scale conformational
changes upon completion of the lipoate adenylation reaction: movements of the
adenylate-binding and lipoate-binding loops to maintain the lipoyl-5'-AMP
reaction intermediate and rotation of the C-terminal domain by about 180 degrees
. These changes are prerequisites for LplA to accommodate apoprotein for the
second reaction. The Lys(133) residue plays essential roles in both lipoate
adenylation and lipoate transfer reactions. Based on structural and kinetic
data, we propose a reaction mechanism driven by conformational changes.
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