1qjo
From Proteopedia
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==Overview== | ==Overview== | ||
| - | The three lipoyl (E2plip) domains of the dihydrolipoyl acetyltransferase, component of the pyruvate dehydrogenase (PDH) complex of Escherichia coli, house the lipoyl-lysine side chain essential for active-site coupling and, substrate channelling within the complex. The structure of the, unlipoylated form of the innermost domain (E2plip(apo)) was determined by, multidimensional NMR spectroscopy and found to resemble closely that of a, nonfunctional hybrid domain determined previously [Green et al. (1995) J., Mol. Biol. 248, 328-343]. The domain comprises two four-stranded, beta-sheets, with the target lysine residue residing at the tip of a, type-I beta-turn in one of the sheets; the N- and C-termini lie close, together at the opposite end of the molecule in the other beta-sheet., | + | The three lipoyl (E2plip) domains of the dihydrolipoyl acetyltransferase, component of the pyruvate dehydrogenase (PDH) complex of Escherichia coli, house the lipoyl-lysine side chain essential for active-site coupling and, substrate channelling within the complex. The structure of the, unlipoylated form of the innermost domain (E2plip(apo)) was determined by, multidimensional NMR spectroscopy and found to resemble closely that of a, nonfunctional hybrid domain determined previously [Green et al. (1995) J., Mol. Biol. 248, 328-343]. The domain comprises two four-stranded, beta-sheets, with the target lysine residue residing at the tip of a, type-I beta-turn in one of the sheets; the N- and C-termini lie close, together at the opposite end of the molecule in the other beta-sheet., Measurement of (15)N NMR relaxation parameters and backbone, hydrogen/deuterium (H/D) exchange rates reveals that the residues in and, surrounding the lipoyl-lysine beta-turn in the E2plip(apo) form of the, domain become less flexible after lipoylation of the lysine residue. This, implies that the lipoyl-lysine side chain may not sample the full range of, conformational space once thought. Moreover, reductive acetylation of the, lipoylated domain (E2plip(holo) --> E2plip(redac)) was accompanied by, large changes in chemical shift between the two forms, and multiple, resonances were observed for several residues. This implies a change in, conformation and the existence of multiple conformations of the domain on, reductive acetylation, which may be important in stabilizing this, catalytic intermediate. |
==About this Structure== | ==About this Structure== | ||
| - | 1QJO is a | + | 1QJO is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Structure known Active Site: 41K. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1QJO OCA]. |
==Reference== | ==Reference== | ||
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[[Category: pyruvate dehydrogenase]] | [[Category: pyruvate dehydrogenase]] | ||
| - | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 14:02:56 2007'' |
Revision as of 11:57, 5 November 2007
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INNERMOST LIPOYL DOMAIN OF THE PYRUVATE DEHYDROGENASE FROM ESCHERICHIA COLI
Overview
The three lipoyl (E2plip) domains of the dihydrolipoyl acetyltransferase, component of the pyruvate dehydrogenase (PDH) complex of Escherichia coli, house the lipoyl-lysine side chain essential for active-site coupling and, substrate channelling within the complex. The structure of the, unlipoylated form of the innermost domain (E2plip(apo)) was determined by, multidimensional NMR spectroscopy and found to resemble closely that of a, nonfunctional hybrid domain determined previously [Green et al. (1995) J., Mol. Biol. 248, 328-343]. The domain comprises two four-stranded, beta-sheets, with the target lysine residue residing at the tip of a, type-I beta-turn in one of the sheets; the N- and C-termini lie close, together at the opposite end of the molecule in the other beta-sheet., Measurement of (15)N NMR relaxation parameters and backbone, hydrogen/deuterium (H/D) exchange rates reveals that the residues in and, surrounding the lipoyl-lysine beta-turn in the E2plip(apo) form of the, domain become less flexible after lipoylation of the lysine residue. This, implies that the lipoyl-lysine side chain may not sample the full range of, conformational space once thought. Moreover, reductive acetylation of the, lipoylated domain (E2plip(holo) --> E2plip(redac)) was accompanied by, large changes in chemical shift between the two forms, and multiple, resonances were observed for several residues. This implies a change in, conformation and the existence of multiple conformations of the domain on, reductive acetylation, which may be important in stabilizing this, catalytic intermediate.
About this Structure
1QJO is a Single protein structure of sequence from Escherichia coli. Structure known Active Site: 41K. Full crystallographic information is available from OCA.
Reference
Restricted motion of the lipoyl-lysine swinging arm in the pyruvate dehydrogenase complex of Escherichia coli., Jones DD, Stott KM, Howard MJ, Perham RN, Biochemistry. 2000 Jul 25;39(29):8448-59. PMID:10913250
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