Research

Post-translational modification in the archaea: structural characterization of multi-enzyme complex lipoylation


Reference:

Posner, M. G., Upadhyay, A., Crennell, S., Watson, A. J. A., Dorus, S., Danson, M. J. and Bagby, S., 2013. Post-translational modification in the archaea: structural characterization of multi-enzyme complex lipoylation. Biochemical Journal, 449 (2), pp. 415-425.

Related documents:

[img]
Preview
PDF (Author's accepted version) - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Download (3972kB) | Preview

    Official URL:

    http://dx.doi.org/10.1042/BJ20121150

    Abstract

    Lipoylation, the covalent attachment of lipoic acid to 2-oxoacid dehydrogenase multi-enzyme complexes, is essential for metabolism in aerobic bacteria and eukarya. In Escherichia coli, lipoylation is catalysed by lipoate protein ligase (LplA) or by lipoic acid synthetase (LipA) and lipoyl(octanoyl) transferase (LipB) combined. Whereas bacterial and eukaryotic LplAs comprise a single, two-domain protein, archaeal LplA function typically involves two proteins, LplA-N and LplA-C. In the thermophilic archaeon Thermoplasma acidophilum, LplA-N and LplA-C are encoded by overlapping genes in inverted orientation (lpla-c is upstream of lpla-n). The structure of Thermoplasma acidophilum LplA-N is known, but the structure of LplA-C and its role in lipoylation are unknown. We have determined the structures of the substrate-free LplA-N+LplA-C complex and the dihydrolipoyl acyltransferase lipoyl domain (E2lipD) that is lipoylated by LplA-N+LplA-C, and carried out biochemical analyses of this archaeal lipoylation system. Our data reveal the following: LplA-C is disordered but folds upon association with LplA-N; LplA-C induces a conformational change in LplA-N involving substantial shortening of a loop that could repress catalytic activity of isolated LplA-N; the adenylate binding region of LplA-N+LplA-C includes two helices rather than the purely loop structure of varying order observed in other LplA structures; LplA-N+LplA-C and E2lipD do not interact in the absence of substrate; LplA-N+LplA-C undergoes a conformational change (the details of which are currently undetermined) during lipoylation; LplA-N+LplA-C can utilize octanoic acid as well as lipoic acid as substrate. The elucidated functional inter-dependence of LplA-N and LplA-C is consistent with their evolutionary co-retention in archaeal genomes.

    Details

    Item Type Articles
    CreatorsPosner, M. G., Upadhyay, A., Crennell, S., Watson, A. J. A., Dorus, S., Danson, M. J. and Bagby, S.
    DOI10.1042/BJ20121150
    Uncontrolled Keywordsbinding-induced folding, lipoate protein ligase, lipoyl domain, nmr spectroscopy, protein-protein interaction, x-ray crystallography
    DepartmentsFaculty of Science > Biology & Biochemistry
    Research CentresCentre for Extremophile Research (CER)
    Centre for Sustainable Chemical Technologies
    Publisher StatementBagby_Biochemical_Journal_2012_1150.pdf: The final version of record is available at http://www.biochemj.org/bj/
    RefereedYes
    StatusPublished
    ID Code32234

    Export

    Actions (login required)

    View Item

    Document Downloads

    More statistics for this item...