1rpv
From Proteopedia
HIV-1 REV PROTEIN (RESIDUES 34-50)
Structural highlights
Function[REV_HV1BN] Escorts unspliced or incompletely spliced viral pre-mRNAs (late transcripts) out of the nucleus of infected cells. These pre-mRNAs carry a recognition sequence called Rev responsive element (RRE) located in the env gene, that is not present in fully spliced viral mRNAs (early transcripts). This function is essential since most viral proteins are translated from unspliced or partially spliced pre-mRNAs which cannot exit the nucleus by the pathway used by fully processed cellular mRNAs. Rev itself is translated from a fully spliced mRNA that readily exits the nucleus. Rev's nuclear localization signal (NLS) binds directly to KPNB1/Importin beta-1 without previous binding to KPNA1/Importin alpha-1. KPNB1 binds to the GDP bound form of RAN (Ran-GDP) and targets Rev to the nucleus. In the nucleus, the conversion from Ran-GDP to Ran-GTP dissociates Rev from KPNB1 and allows Rev's binding to the RRE in viral pre-mRNAs. Rev multimerization on the RRE via cooperative assembly exposes its nuclear export signal (NES) to the surface. Rev can then form a complex with XPO1/CRM1 and Ran-GTP, leading to nuclear export of the complex. Conversion from Ran-GTP to Ran-GDP mediates dissociation of the Rev/RRE/XPO1/RAN complex, so that Rev can return to the nucleus for a subsequent round of export. Beside KPNB1, also seems to interact with TNPO1/Transportin-1, RANBP5/IPO5 and IPO7/RANBP7 for nuclear import. The nucleoporin-like HRB/RIP is an essential cofactor that probably indirectly interacts with Rev to release HIV RNAs from the perinuclear region to the cytoplasm (By similarity). Publication Abstract from PubMedNMR spectroscopy has been used to solve the three-dimensional solution structure of a minimal RNA-binding domain of the Rev protein from the human immunodeficiency virus (type 1), an essential regulatory protein for viral replication. The presence of 10 arginine residues in the 17-residue peptide Rev34-50 caused significant problems in assignment of the NMR spectra. To improve spectral resolution, the peptide was synthesized with an alanine replacing a nonessential arginine and with selectively 15N-labeled residues. Contrary to Chou-Fasman modeling predictions an alpha-helix was detected in both water and 20% trifluoroethanol (TFE) and was found to span residues that constitute the RNA-binding and nuclear-localizing domains of Rev. The sequence-specific information provided by the NMR data gives a full description of the solution conformation of Rev34-50 which serves as a template for investigating binding of the peptide to RNA from the Rev response element (RRE). Preliminary modeling suggests that the helix can fit neatly into the expanded major groove of the RRE where interactions between the peptide side chains and the RNA can be identified. These data may aid the construction of a suitable pharmacophore model for the rational design of molecules that block Rev-RNA binding and inhibit HIV replication. NMR solution structure of the RNA-binding peptide from human immunodeficiency virus (type 1) Rev.,Scanlon MJ, Fairlie DP, Craik DJ, Englebretsen DR, West ML Biochemistry. 1995 Jul 4;34(26):8242-9. PMID:7599117[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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