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Publication Abstract from PubMed

Transhydrogenase is a proton pump found in the membranes of bacteria and animal mitochondria. The solution structure of the expressed, 21.5 kDa, NADP(H)-binding component (dIII) of transhydrogenase from Rhodospirillum rubrum has been solved by NMR methods. This is the first description of the structure of dIII from a bacterial source. The protein adopts a Rossmann fold: an open, twisted, parallel beta-sheet, flanked by helices. However, the binding of NADP(+) to dIII is profoundly different to that seen in other Rossmann structures, in that its orientation is reversed: the adenosine moiety interacts with the first betaalphabetaalphabeta motif, and the nicotinamide with the second. Features in the structure that might be responsible for changes in nucleotide-binding affinity during catalysis, and for interaction with other components of the enzyme, are identified. The results are compared with the recently determined, high-resolution crystal structures of human and bovine dIII which also show the reversed nucleotide orientation.

Solution structure of the NADP(H)-binding component (dIII) of proton-translocating transhydrogenase from Rhodospirillum rubrum.,Jeeves M, Smith KJ, Quirk PG, Cotton NP, Jackson JB Biochim Biophys Acta. 2000 Aug 15;1459(2-3):248-57. PMID:11004437^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.