6vch

Crystal structure of Nitrosotalea devanaterra carotenoid cleavage dioxygenase in complex with 3-hydroxy-beta-apo-14'-carotenal

spinqualitylabelsall models 6vch, resolution 2.35Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 6vch is a 6 chain structure with sequence from Candidatus Nitrosotalea devanaterra. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.35Å Ligands: CL, CO, NA, QVM Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function A0A128A3G4_9ARCH Publication Abstract from PubMed Apocarotenoids are important signaling molecules generated from carotenoids through the action of carotenoid cleavage dioxygenases (CCDs). These enzymes have a remarkable ability to cleave carotenoids at specific alkene bonds while leaving chemically similar sites within the polyene intact. Although several bacterial and eukaryotic CCDs have been characterized, the long-standing goal of experimentally visualizing a CCD-carotenoid complex at high resolution to explain this exquisite regioselectivity remains unfulfilled. CCD genes are also present in some archaeal genomes, but the encoded enzymes remain uninvestigated. Here, we address this knowledge gap through analysis of a metazoan-like archaeal CCD from Candidatus Nitrosotalea devanaterra (NdCCD). NdCCD was active toward beta-apocarotenoids but did not cleave bicyclic carotenoids. It exhibited an unusual regiospecificity, cleaving apocarotenoids solely at the C14'-C13' alkene bond to produce beta-apo-14'-carotenals. The structure of NdCCD revealed a tapered active site cavity markedly different from the broad active site observed for the retinal-forming Synechocystis apocarotenoid oxygenase (SynACO) but similar to the vertebrate retinoid isomerase RPE65. The structure of NdCCD in complex with its apocarotenoid product demonstrated that the site of cleavage is defined by interactions along the substrate binding cleft as well as selective stabilization of reaction intermediates at the scissile alkene. These data on the molecular basis of CCD catalysis shed light on the origins of the varied catalytic activities found in metazoan CCDs, opening the possibility of modifying their activity through rational chemical or genetic approaches. Structural basis for carotenoid cleavage by an archaeal carotenoid dioxygenase.,Daruwalla A, Zhang J, Lee HJ, Khadka N, Farquhar ER, Shi W, von Lintig J, Kiser PD Proc Natl Acad Sci U S A. 2020 Aug 3. pii: 2004116117. doi:, 10.1073/pnas.2004116117. PMID:32747548 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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