1rhx

Protein Summary

The TM0979 gene of Thermotoga maritima belongs to the DsrH family of conserved bacterial proteins (Pfam04077, COG2168), which are involved in oxidation of intracellular sulfur but have no defined molecular function. Protein encoded by TM0979 has two NMR structures: 1RHX (PubMed:15723348 and 1X9A (PubMed:15608123). In Thermotoga maritima genome, two other open reading frames adjucent to TM0970 encode almost identical proteins.

Other proteins involved in sulfur metabolism with sequence similarity to TM0979 are found as a component of heterohexameric complexes, such as DsrH from DsrEFH complex (PubMed:15687204) and TusB (tRNA 2-thiouridine synthesizing protein B)TusBCD complex (PubMed:16472754; DALI Z-score=9.8, RMSD=1.9 for 77 amino acids between PDB structures 1X9A:A and 2D1P:F).

The TM0979 structure contains in the sequence order ?-?-?-?-?-?-(3₁₀)-?, where three-stranded parallel ?-sheet, located in the center of the protein is surrounded by the five helices (PubMed:15608123).

Structure of TM0979 from T. maritima can be expected to contribute towards establishing the actual function of the DsrH protein and other members of this family potentially involved in sulfur metabolism.

Figure 1. (attached below) TM0979 dimer (PDB id 1X9A) with surface colored according to sequence conservation in homologous proteins (red = conserved). Many conserved residues are clustered close to one side of the dimer interface as shown on the right side (subfigure D).

Sulfur transferase activity predicted for DsrEFG based on conservation of catalytic residues/comparison with TusBCD [Ref].

Ligand Summary

References