5fsw

RNA dependent RNA polymerase QDE-1 from Thielavia terrestris

spinqualitylabelsall models 5fsw, resolution 3.19Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 5fsw is a 4 chain structure with sequence from Thermothielavioides terrestris. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 3.19Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function G2R911_THETT Publication Abstract from PubMed Many eukaryotic organisms encode more than one RNA-dependent RNA polymerase (RdRP) that likely emerged as a result of gene duplication. Such RdRP paralogs often participate in distinct RNA silencing pathways and show characteristic repertoires of enzymatic activities in vitro. However, to what extent members of individual paralogous groups can undergo functional changes during speciation remains an open question. We show that orthologs of QDE-1, an RdRP component of the quelling pathway in Neurospora crassa, have rapidly diverged in evolution at the amino acid sequence level. Analyses of purified QDE-1 polymerases from N. crassa (QDE-1Ncr) and related fungi, Thielavia terrestris (QDE-1Tte) and Myceliophthora thermophila (QDE-1Mth), show that all three enzymes can synthesize RNA but the precise modes of their action differ considerably. Unlike their QDE-1Ncr counterpart favoring processive RNA synthesis, QDE-1Tte and QDE-1Mth produce predominantly short RNA copies via primer-independent initiation. Surprisingly, a 3.19 A-resolution crystal structure of QDE-1Tte reveals a quasi-symmetric dimer similar to QDE-1Ncr. Further electron microscopy analyses confirm that QDE-1Tte occurs as a dimer in solution and retains this status upon interaction with a template. We conclude that divergence of orthologous RdRPs can result in functional innovation while retaining overall protein fold and quaternary structure. Functional Evolution in Orthologous Cell-encoded RNA-dependent RNA Polymerases.,Qian X, Hamid FM, El Sahili A, Darwis DA, Wong YH, Bhushan S, Makeyev EV, Lescar J J Biol Chem. 2016 Feb 23. pii: jbc.M115.685933. PMID:26907693 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also RNA polymerase 3D structures

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