1pno

Crystal structure of R. rubrum transhydrogenase domain III bound to NADPCrystal structure of R. rubrum transhydrogenase domain III bound to NADP

Structural highlights 1pno is a 2 chain structure with sequence from "dicrospirillum_rubrum"_enderlein_1925 "dicrospirillum rubrum" enderlein 1925. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: Related: 1pnq Gene: PNTB OR NNTB ("Dicrospirillum rubrum" Enderlein 1925) Activity: NAD(P)(+) transhydrogenase (Re/Si-specific), with EC number 1.6.1.2 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum Function [PNTB_RHORU] The transhydrogenation between NADH and NADP is coupled to respiration and ATP hydrolysis and functions as a proton pump across the membrane (By similarity). 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 Proton-translocating transhydrogenase (TH) couples direct and stereospecific hydride transfer between NAD(H) and NADP(H), bound to soluble domains dI and dIII, respectively, to proton translocation across a membrane bound domain, dII. The reaction occurs with proton-gradient coupled conformational changes, which affect the energetics of substrate binding and interdomain interactions. The crystal structure of TH dIII from Rhodospirillum rubrum has been determined in the presence of NADPH (2.4 A) and NADP (2.1 A) (space group P6(1)22). Each structure has two molecules in the asymmetric unit, differing in the conformation of the NADP(H) binding loop D. In one molecule, loop D has an open conformation, with the B face of (dihydro)nicotinamide exposed to solvent. In the other molecule, loop D adopts a hitherto unobserved closed conformation, resulting in close interactions between NADP(H) and side chains of the highly conserved residues, betaSer405, betaPro406, and betaIle407. The conformational change shields the B face of (dihydro)nicotinamide from solvent, which would block hydride transfer in the intact enzyme. It also alters the environments of invariant residues betaHis346 and betaAsp393. However, there is little difference in either the open or the closed conformation upon change in oxidation state of nicotinamide, i.e., for NADP vs. NADPH. Consequently, the occurrence of two loop D conformations for both substrate oxidation states gives rise to four states: NADP-open, NADP-closed, NADPH-open, and NADPH-closed. Because these states are distinguished by protein conformation and by net charge they may be important in the proton translocating mechanism of intact TH. Conformational change in the NADP(H) binding domain of transhydrogenase defines four states.,Sundaresan V, Yamaguchi M, Chartron J, Stout CD Biochemistry. 2003 Oct 28;42(42):12143-53. PMID:14567675 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also NAD(P) transhydrogenase

spinqualitylabelsall models 1pno, resolution 2.10Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image