2ihx
From Proteopedia
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Solution Structure of the Rous Sarcoma Virus Nucleocapsid Protein:uPsi RNA Packaging Signal Complex
Overview
The 5'-untranslated region (5'-UTR) of retroviral genomes contains, elements required for genome packaging during virus assembly. For many, retroviruses, the packaging elements reside in non-contiguous segments, that span most or all of the 5'-UTR. The Rous sarcoma virus (RSV) is an, exception, in that its genome can be packaged efficiently by a relatively, short, 82 nt segment of the 5'-UTR called muPsi. The RSV 5'-UTR also, contains three translational start codons (AUG-1, AUG-2 and AUG-3) that, have been controvertibly implicated in translation initiation and genome, packaging, one of which (AUG-3) resides within the muPsi sequence. We, demonstrated recently that muPsi is capable of binding to the cognate RSV, nucleocapsid protein (NC) with high affinity (dissociation constant K(d), approximately 2 nM), and that residues of AUG-3 are essential for tight, binding. We now report the solution structure of the NC:muPsi complex, determined using NMR data obtained for samples containing, ((13)C,(15)N)-labeled NC and (2)H-enriched, nucleotide-specifically, protonated RNAs. Upon NC binding, muPsi adopts a stable secondary, structure that consists of three stem loops (SL-A, SL-B and SL-C) and an 8, bp stem (O3). Binding is mediated by the two zinc knuckle domains of NC., The N-terminal knuckle interacts with a conserved U(217)GCG tetraloop (a, member of the UNCG family; N=A,U,G or C), and the C-terminal zinc knuckle, binds to residues that flank SL-A, including residues of AUG-3. Mutations, of critical nucleotides in these sequences compromise or abolish viral, infectivity. Our studies reveal novel structural features important for, NC:RNA binding, and support the hypothesis that AUG-3 is conserved for, genome packaging rather than translational control.
About this Structure
2IHX is a Single protein structure of sequence from Rous sarcoma virus with as ligand. Full crystallographic information is available from OCA.
Reference
Solution structure of the Rous sarcoma virus nucleocapsid protein: muPsi RNA packaging signal complex., Zhou J, Bean RL, Vogt VM, Summers M, J Mol Biol. 2007 Jan 12;365(2):453-67. Epub 2006 Oct 10. PMID:17070546
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