1gjx: Difference between revisions

[[Image:1gjx.gif|left|200px]]<br /><applet load="1gjx" size="350" color="white" frame="true" align="right" spinBox="true"  

The antigenic P64K protein from the pathogenic bacterium Neisseria meningitidis is found in the outer membrane of the cell, and consists of two parts: an 81-residue N-terminal region and a 482-residue C-terminal region. The amino-acid sequence of the N-terminal region is homologous with the lipoyl domains of the dihydrolipoyl acyltransferase (E2) components, and that of the C-terminal region with the dihydrolipoyl dehydrogenase (E3) components, of 2-oxo acid dehydrogenase multienzyme complexes. The two parts are separated by a long linker region, similar to the linker regions in the E2 chains of 2-oxo acid dehydrogenase complexes, and it is likely this region is conformationally flexible. A subgene encoding the P64K lipoyl domain was created and over-expressed in Escherichia coli. The product was capable of post-translational modification by the lipoate protein ligase but not aberrant modification by the biotin protein ligase of E. coli. The solution structure of the apo-domain was determined by means of heteronuclear NMR spectroscopy and found to be a flattened beta barrel composed of two four-stranded antiparallel beta sheets. The lysine residue that becomes lipoylated is in an exposed beta turn that, from a [1H]-15N heteronuclear Overhauser effect experiment, appears to enjoy substantial local motion. This structure of a lipoyl domain derived from a dihydrolipoyl dehydrogenase resembles that of lipoyl domains normally found as part of the dihydrolipoyl acyltransferase component of 2-oxo acid dehydrogenase complexes and will assist in furthering the understanding of its function in a multienzyme complex and in the membrane-bound P64K protein itself.

1GJX is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Neisseria_meningitidis Neisseria meningitidis]. Active as [http://en.wikipedia.org/wiki/Dihydrolipoyl_dehydrogenase Dihydrolipoyl dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.8.1.4 1.8.1.4] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1GJX OCA].  

[[Category: Broadhurst, R W.]]

[[Category: Perham, R N.]]

[[Category: Raine, A R.C.]]

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