2d1p
From Proteopedia
crystal structure of heterohexameric TusBCD proteins, which are crucial for the tRNA modification
Structural highlights
Function[TUSD_ECOLI] Part of a sulfur-relay system required for 2-thiolation of 5-methylaminomethyl-2-thiouridine (mnm(5)s(2)U) at tRNA wobble positions. Accepts sulfur from TusA and transfers it in turn to TusE.[1] [TUSB_ECOLI] Part of a sulfur-relay system required for 2-thiolation of 5-methylaminomethyl-2-thiouridine (mnm(5)s(2)U) at tRNA wobble positions.[2] [TUSC_ECOLI] Part of a sulfur-relay system required for 2-thiolation of 5-methylaminomethyl-2-thiouridine (mnm(5)s(2)U) at tRNA wobble positions.[3] 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 PubMedUridine at wobble position 34 of tRNA(Lys), tRNA(Glu), and tRNA(Gln) is exclusively modified into 2-thiouridine (s2U), which is crucial for both precise codon recognition and recognition by the cognate aminoacyl-tRNA synthetases. Recent Escherichia coli genetic studies revealed that the products of five novel genes, tusABCDE, function in the s2U modification. Here, we solved the 2.15 angstroms crystal structure of the E. coli TusBCD complex, a sulfur transfer mediator, forming a heterohexamer composed of a dimer of the heterotrimer. Structure-based sequence alignment suggested two putative active site Cys residues, Cys79 (in TusC) and Cys78 (in TusD), which are exposed on the hexameric complex. In vivo mutant analyses revealed that only Cys78, in the TusD subunit, participates in sulfur transfer during the s2U modification process. Since the single Cys acts as a catalytic residue, we proposed that TusBCD mediates sulfur relay via a putative persulfide state of the TusD subunit. Structural basis for sulfur relay to RNA mediated by heterohexameric TusBCD complex.,Numata T, Fukai S, Ikeuchi Y, Suzuki T, Nureki O Structure. 2006 Feb;14(2):357-66. PMID:16472754[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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