3a7a
From Proteopedia
Crystal structure of E. coli lipoate-protein ligase A in complex with octyl-amp and apoH-protein
Structural highlights
FunctionLPLA_ECOLI Catalyzes both the ATP-dependent activation of exogenously supplied lipoate to lipoyl-AMP and the transfer of the activated lipoyl onto the lipoyl domains of lipoate-dependent enzymes. Is also able to catalyze very poorly the transfer of lipoyl and octanoyl moiety from their acyl carrier protein.[1] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedLipoate-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. Global conformational change associated with the two-step reaction catalyzed by Escherichia coli lipoate-protein ligase A.,Fujiwara K, Maita N, Hosaka H, Okamura-Ikeda K, Nakagawa A, Taniguchi H J Biol Chem. 2010 Mar 26;285(13):9971-80. Epub 2010 Jan 19. PMID:20089862[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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