1zn1
From Proteopedia
Coordinates of RRF fitted into Cryo-EM map of the 70S post-termination complex
Structural highlights
Function[RS12_ECOLI] With S4 and S5 plays an important role in translational accuracy.[HAMAP-Rule:MF_00403_B] Interacts with and stabilizes bases of the 16S rRNA that are involved in tRNA selection in the A site and with the mRNA backbone. Located at the interface of the 30S and 50S subunits, it traverses the body of the 30S subunit contacting proteins on the other side and probably holding the rRNA structure together. The combined cluster of proteins S8, S12 and S17 appears to hold together the shoulder and platform of the 30S subunit (By similarity).[HAMAP-Rule:MF_00403_B] Cryo-EM studies suggest that S12 contacts the EF-Tu bound tRNA in the A-site during codon-recognition. This contact is most likely broken as the aminoacyl-tRNA moves into the peptidyl transferase center in the 50S subunit.[HAMAP-Rule:MF_00403_B] [RRF_ECOLI] Responsible for the release of ribosomes from messenger RNA at the termination of protein biosynthesis. May increase the efficiency of translation by recycling ribosomes from one round of translation to another.[HAMAP-Rule:MF_00040] Evolutionary Conservation Checkto colour the structure by Evolutionary Conservation, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedRibosome recycling, the disassembly of the posttermination complex after each round of protein synthesis, is an essential step in mRNA translation, but its mechanism has remained obscure. In eubacteria, recycling is catalyzed by RRF (ribosome recycling factor) and EF-G (elongation factor G). By using cryo-electron microscopy, we have obtained two density maps, one of the RRF bound posttermination complex and one of the 50S subunit bound with both EF-G and RRF. Comparing the two maps, we found domain I of RRF to be in the same orientation, while domain II in the EF-G-containing 50S subunit is extensively rotated (approximately 60 degrees) compared to its orientation in the 70S complex. Mapping the 50S conformation of RRF onto the 70S posttermination complex suggests that it can disrupt the intersubunit bridges B2a and B3, and thus effect a separation of the two subunits. These observations provide the structural basis for the mechanism by which the posttermination complex is split into subunits by the joint action of RRF and EF-G. Mechanism for the disassembly of the posttermination complex inferred from cryo-EM studies.,Gao N, Zavialov AV, Li W, Sengupta J, Valle M, Gursky RP, Ehrenberg M, Frank J Mol Cell. 2005 Jun 10;18(6):663-74. PMID:15949441[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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