Structural highlights
Disease
[ODB2_HUMAN] Defects in DBT are the cause of maple syrup urine disease type 2 (MSUD2) [MIM:248600]. MSUD is an autosomal recessive disorder characterized by mental and physical retardation, feeding problems, and a maple syrup odor to the urine.[1] [2]
Function
[ODB2_HUMAN] The branched-chain alpha-keto dehydrogenase complex catalyzes the overall conversion of alpha-keto acids to acyl-CoA and CO(2). It contains multiple copies of three enzymatic components: branched-chain alpha-keto acid decarboxylase (E1), lipoamide acyltransferase (E2) and lipoamide dehydrogenase (E3).
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 PubMed
The lipoyl-bearing domain (LBD) of the transacylase (E2) subunit of the branched-chain alpha-keto acid dehydrogenase complex plays a central role in substrate channeling in this mitochondrial multienzyme complex. We have employed multidimensional heteronuclear NMR techniques to determine the structure and dynamics of the LBD of the human branched-chain alpha-keto acid dehydrogenase complex (hbLBD). Similar to LBD from other members of the alpha-keto acid dehydrogenase family, the solution structure of hbLBD is a flattened beta-barrel formed by two four-stranded antiparallel beta-sheets. The lipoyl Lys(44) residue resides at the tip of a beta-hairpin comprising a sharp type I beta-turn and the two connecting beta-strands 4 and 5. A prominent V-shaped groove formed by a surface loop, L1, connecting beta 1- and beta 2-strands and the lipoyl lysine beta-hairpin constitutes the functional pocket. We further applied reduced spectral density functions formalism to extract dynamic information of hbLBD from (15)N-T(1), (15)N-T(2), and ((1)H-(15)N) nuclear Overhauser effect data obtained at 600 MHz. The results showed that residues surrounding the lipoyl lysine region comprising the L1 loop and the Lys(44) beta-turn are highly flexible, whereas beta-sheet S1 appears to display a slow conformational exchange process.
Solution structure and dynamics of the lipoic acid-bearing domain of human mitochondrial branched-chain alpha-keto acid dehydrogenase complex.,Chang CF, Chou HT, Chuang JL, Chuang DT, Huang TH J Biol Chem. 2002 May 3;277(18):15865-73. Epub 2002 Feb 11. PMID:11839747[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Fisher CW, Lau KS, Fisher CR, Wynn RM, Cox RP, Chuang DT. A 17-bp insertion and a Phe215----Cys missense mutation in the dihydrolipoyl transacylase (E2) mRNA from a thiamine-responsive maple syrup urine disease patient WG-34. Biochem Biophys Res Commun. 1991 Jan 31;174(2):804-9. PMID:1847055
- ↑ Tsuruta M, Mitsubuchi H, Mardy S, Miura Y, Hayashida Y, Kinugasa A, Ishitsu T, Matsuda I, Indo Y. Molecular basis of intermittent maple syrup urine disease: novel mutations in the E2 gene of the branched-chain alpha-keto acid dehydrogenase complex. J Hum Genet. 1998;43(2):91-100. PMID:9621512 doi:10.1007/s100380050047
- ↑ Chang CF, Chou HT, Chuang JL, Chuang DT, Huang TH. Solution structure and dynamics of the lipoic acid-bearing domain of human mitochondrial branched-chain alpha-keto acid dehydrogenase complex. J Biol Chem. 2002 May 3;277(18):15865-73. Epub 2002 Feb 11. PMID:11839747 doi:http://dx.doi.org/10.1074/jbc.M110952200
