3wjq

Crystal structure of the HypE CN form

spinqualitylabelsall models 3wjq, resolution 1.65Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3wjq is a 1 chain structure with sequence from Thermococcus kodakarensis KOD1. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.645Å Ligands: ATP, BEN, GOL, MG, PEG, PGE, PO4, SO4, XCN Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q5JII7_THEKO Publication Abstract from PubMed Hydrogenase pleiotropically acting protein (Hyp)E plays a role in biosynthesis of the cyano groups for the NiFe(CN)2CO center of [NiFe] hydrogenases by catalyzing the ATP-dependent dehydration of the carbamoylated C-terminal cysteine of HypE to thiocyanate. Although structures of HypE proteins have been determined, until now there has been no structural evidence to explain how HypE dehydrates thiocarboxamide into thiocyanate. Here, we report the crystal structures of the carbamoylated and cyanated forms of HypE from Thermococcus kodakarensis in complex with nucleotides at 1.53- and 1.64-A resolution, respectively. Carbamoylation of the C-terminal cysteine (Cys338) of HypE by chemical modification is clearly observed in the present structures. In the presence of ATP, the thiocarboxamide of Cys338 is successfully dehydrated into the thiocyanate. In the carbamoylated state, the thiocarboxamide nitrogen atom of Cys338 is close to a conserved glutamate residue (Glu272), but the spatial position of Glu272 is less favorable for proton abstraction. On the other hand, the thiocarboxamide oxygen atom of Cys338 interacts with a conserved lysine residue (Lys134) through a water molecule. The close contact of Lys134 with an arginine residue lowers the pKa of Lys134, suggesting that Lys134 functions as a proton acceptor. These observations suggest that the dehydration of thiocarboxamide into thiocyanate is catalyzed by a two-step deprotonation process, in which Lys134 and Glu272 function as the first and second bases, respectively. Crystal structures of the carbamoylated and cyanated forms of HypE for [NiFe] hydrogenase maturation.,Tominaga T, Watanabe S, Matsumi R, Atomi H, Imanaka T, Miki K Proc Natl Acad Sci U S A. 2013 Dec 2. PMID:24297906 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also HypA%2C HypB%2C HypC%2C HypD%2C HypE and HypF 3D structures

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