3a4n | pdb_00003a4n

Crystal structure of archaeal O-phosphoseryl-tRNA(Sec) kinase

spinqualitylabelsall models 3a4n, resolution 2.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3a4n is a 2 chain structure with sequence from Atcc 43067. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: EDO, IOD, PO4 Related: 3a4l, 3a4m Gene: MJ1538 (ATCC 43067) Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [PSTK_METJA] Specifically phosphorylates seryl-tRNA(Sec) to O-phosphoseryl-tRNA(Sec), an activated intermediate for selenocysteine biosynthesis. 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 Compared to bacteria, archaea and eukaryotes employ an additional enzyme for the biosynthesis of selenocysteine (Sec), the 21(st) natural amino acid (aa). An essential RNA-dependent kinase, O-phosphoseryl-tRNA(Sec) kinase (PSTK), converts seryl-tRNA(Sec) to O-phosphoseryl-tRNA(Sec), the immediate precursor of selenocysteinyl-tRNA(Sec). The sequence of Methanocaldococcus jannaschii PSTK (MjPSTK) suggests an N-terminal kinase domain (177 aa) followed by a presumed tRNA binding region (75 aa). The structures of MjPSTK complexed with ADP and AMPPNP revealed that this enzyme belongs to the P-loop kinase class, and that the kinase domain is closely related to gluconate kinase and adenylate kinase. ATP is bound by the P-loop domain (residues 11-18). Formed by antiparallel dimerization of two PSTK monomers, the enzyme structure shows a deep groove with positive electrostatic potential. Located in this groove is the enzyme's active site, which biochemical and genetic data suggest is composed of Asp-41, Arg-44, Glu-55, Tyr-82, Tyr-83, Met-86, and Met-132. Based on structural comparison with Escherichia coli adenylate kinase a docking model was generated that assigns these amino acids to the recognition of the terminal A76-Ser moieties of Ser-tRNA(Sec). The geometry and electrostatic environment of the groove in MjPSTK are perfectly complementary to the unusually long acceptor helix of tRNA(Sec). Structure of a tRNA-dependent kinase essential for selenocysteine decoding.,Araiso Y, Sherrer RL, Ishitani R, Ho JM, Soll D, Nureki O Proc Natl Acad Sci U S A. 2009 Sep 22;106(38):16215-20. Epub 2009 Sep 10. PMID:19805283 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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