Structural highlights
Function[SRP14_HUMAN] Signal-recognition-particle assembly has a crucial role in targeting secretory proteins to the rough endoplasmic reticulum membrane. SRP9 together with SRP14 and the Alu portion of the SRP RNA, constitutes the elongation arrest domain of SRP. The complex of SRP9 and SRP14 is required for SRP RNA binding. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedCotranslational translocation of proteins across or into membranes is a vital process in all kingdoms of life. It requires that the translating ribosome be targeted to the membrane by the signal recognition particle (SRP), an evolutionarily conserved ribonucleoprotein particle. SRP recognizes signal sequences of nascent protein chains emerging from the ribosome. Subsequent binding of SRP leads to a pause in peptide elongation and to the ribosome docking to the membrane-bound SRP receptor. Here we present the structure of a targeting complex consisting of mammalian SRP bound to an active 80S ribosome carrying a signal sequence. This structure, solved to 12 A by cryo-electron microscopy, enables us to generate a molecular model of SRP in its functional conformation. The model shows how the S domain of SRP contacts the large ribosomal subunit at the nascent chain exit site to bind the signal sequence, and that the Alu domain reaches into the elongation-factor-binding site of the ribosome, explaining its elongation arrest activity. Structure of the signal recognition particle interacting with the elongation-arrested ribosome.,Halic M, Becker T, Pool MR, Spahn CM, Grassucci RA, Frank J, Beckmann R Nature. 2004 Feb 26;427(6977):808-14. PMID:14985753[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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