The lipoamide arm in the glycine decarboxylase complex is not freely swinging.Cohen-Addad, C., Pares, S., Sieker, L., Neuburger, M., Douce, R.
(1995) Nat Struct Biol 2: 63-68
- PubMed: 7719855
- DOI: https://doi.org/10.1038/nsb0195-63
- Primary Citation of Related Structures:
- PubMed Abstract:
Glycine decarboxylase consists of four protein components. Its structural and mechanistic heart is provided by the lipoic acid-containing H-protein which undergoes a cycle of reductive methylamination, methylamine transfer and electron transfer. Lipoic acid attached to a specific lysine side chain is assumed to act as a 'swinging arm' conveying the reactive dithiolane ring from one catalytic centre to another. The X-ray crystal structures of two forms of the H-protein have been determined. The lipoate cofactor is located in the loop of a hairpin configuration but following methylamine transfer it is pivoted to bind into a cleft at the surface of the H-protein. The lipoamide-methylamine arm is, therefore, not free to move in aqueous solvent.
Institut de Biologie Structurale, Centre National de la Recherche Scientifique et Commisariat à l'Energie Atomique, Grenoble, France.