Publication Date:
2014-04-05
Description:
The signal recognition particle (SRP) is central to membrane protein targeting; SRP RNA is essential for SRP assembly, elongation arrest, and activation of SRP guanosine triphosphatases. In eukaryotes, SRP function relies on the SRP68-SRP72 heterodimer. We present the crystal structures of the RNA-binding domain of SRP68 (SRP68-RBD) alone and in complex with SRP RNA and SRP19. SRP68-RBD is a tetratricopeptide-like module that binds to a RNA three-way junction, bends the RNA, and inserts an alpha-helical arginine-rich motif (ARM) into the major groove. The ARM opens the conserved 5f RNA loop, which in ribosome-bound SRP establishes a contact to ribosomal RNA. Our data provide the structural basis for eukaryote-specific, SRP68-driven RNA remodeling required for protein translocation.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Grotwinkel, Jan Timo -- Wild, Klemens -- Segnitz, Bernd -- Sinning, Irmgard -- New York, N.Y. -- Science. 2014 Apr 4;344(6179):101-4. doi: 10.1126/science.1249094.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24700861" target="_blank"〉PubMed〈/a〉
Keywords:
Crystallography, X-Ray
;
Humans
;
Hydrophobic and Hydrophilic Interactions
;
Models, Molecular
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Nucleic Acid Conformation
;
Protein Binding
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Protein Conformation
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Protein Multimerization
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Protein Structure, Secondary
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Protein Structure, Tertiary
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*Protein Transport
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RNA, Ribosomal/chemistry/metabolism
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RNA, Small Cytoplasmic/*chemistry/*metabolism
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Ribosomes
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Signal Recognition Particle/*chemistry/genetics/metabolism
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics