2gxu
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(New page: 200px<br /><applet load="2gxu" size="350" color="white" frame="true" align="right" spinBox="true" caption="2gxu, resolution 1.67Å" /> '''HERA N-terminal doma...)
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Revision as of 18:10, 29 January 2008
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HERA N-terminal domain in complex with orthophosphate, crystal form 1
Overview
DEAD box RNA helicases use the energy of ATP hydrolysis to unwind, double-stranded RNA regions or to disrupt RNA/protein complexes. A minimal, RNA helicase comprises nine conserved motifs distributed over two, RecA-like domains. The N-terminal domain contains all motifs involved in, nucleotide binding, namely the Q-motif, the DEAD box, and the P-loop, as, well as the SAT motif, which has been implicated in the coordination of, ATP hydrolysis and RNA unwinding. We present here the crystal structure of, the N-terminal domain of the Thermus thermophilus RNA helicase Hera in, complex with adenosine monophosphate (AMP). Upon binding of AMP the P-loop, adopts a partially collapsed or half-open conformation that is still, connected to the DEAD box motif, and the DEAD box in turn is linked to the, SAT motif via hydrogen bonds. This network of interactions communicates, changes in the P-loop conformation to distant parts of the helicase. The, affinity of AMP is comparable to that of ADP and ATP, substantiating that, the binding energy from additional phosphate moieties is directly, converted into conformational changes of the entire helicase. Importantly, the N-terminal Hera domain forms a dimer in the crystal similar to that, seen in another thermophilic prokaryote. It is possible that this mode of, dimerization represents the prototypic architecture in RNA helicases of, thermophilic origin.
About this Structure
2GXU is a Single protein structure of sequence from Thermus thermophilus with as ligand. Full crystallographic information is available from OCA.
Reference
Crystal structure and nucleotide binding of the Thermus thermophilus RNA helicase Hera N-terminal domain., Rudolph MG, Heissmann R, Wittmann JG, Klostermeier D, J Mol Biol. 2006 Aug 25;361(4):731-43. Epub 2006 Jul 12. PMID:16890241
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