کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2188424 1096168 2007 14 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Structural Insights into the Second Step of RNA-dependent Cysteine Biosynthesis in Archaea: Crystal Structure of Sep-tRNA:Cys-tRNA Synthase from Archaeoglobus fulgidus
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی بیولوژی سلول
پیش نمایش صفحه اول مقاله
Structural Insights into the Second Step of RNA-dependent Cysteine Biosynthesis in Archaea: Crystal Structure of Sep-tRNA:Cys-tRNA Synthase from Archaeoglobus fulgidus
چکیده انگلیسی

In the ancient organisms, methanogenic archaea, lacking the canonical cysteinyl-tRNA synthetase, Cys-tRNACys is produced by an indirect pathway, in which O-phosphoseryl-tRNA synthetase ligates O-phosphoserine (Sep) to tRNACys and Sep-tRNA:Cys-tRNA synthase (SepCysS) converts Sep-tRNACys to Cys-tRNACys. In this study, the crystal structure of SepCysS from Archaeoglobus fulgidus has been determined at 2.4 Å resolution. SepCysS forms a dimer, composed of monomers bearing large and small domains. The large domain harbors the seven-stranded β-sheet, which is typical of the pyridoxal 5′-phosphate (PLP)-dependent enzymes. In the active site, which is located near the dimer interface, PLP is covalently bound to the side-chain of the conserved Lys209. In the proximity of PLP, a sulfate ion is bound by the side-chains of the conserved Arg79, His103, and Tyr104 residues. The active site is located deep within the large, basic cleft to accommodate Sep-tRNACys. On the basis of the surface electrostatic potential, the amino acid residue conservation mapping, the position of the bound sulfate ion, and the substrate amino acid binding manner in other PLP-dependent enzymes, a binding model of Sep-tRNACys to SepCysS was constructed. One of the three strictly conserved Cys residues (Cys39, Cys42, or Cys247), of one subunit may play a crucial role in the catalysis in the active site of the other subunit.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Biology - Volume 370, Issue 1, 29 June 2007, Pages 128–141
نویسندگان
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