4v9m
70S Ribosome translocation intermediate FA-4.2A containing elongation factor EFG/FUSIDIC ACID/GDP, mRNA, and tRNA bound in the pe*/E state.70S Ribosome translocation intermediate FA-4.2A containing elongation factor EFG/FUSIDIC ACID/GDP, mRNA, and tRNA bound in the pe*/E state.
Structural highlights
FunctionRS9_THET2 Part of the top of the head of the 30S subunit. The C-terminal region penetrates the head emerging in the P-site where it contacts tRNA (By similarity). Publication Abstract from PubMedTranslocation of messenger and transfer RNA (mRNA and tRNA) through the ribosome is a crucial step in protein synthesis, whose mechanism is not yet understood. The crystal structures of three Thermus ribosome-tRNA-mRNA-EF-G complexes trapped with beta,gamma-imidoguanosine 5'-triphosphate (GDPNP) or fusidic acid reveal conformational changes occurring during intermediate states of translocation, including large-scale rotation of the 30S subunit head and body. In all complexes, the tRNA acceptor ends occupy the 50S subunit E site, while their anticodon stem loops move with the head of the 30S subunit to positions between the P and E sites, forming chimeric intermediate states. Two universally conserved bases of 16S ribosomal RNA that intercalate between bases of the mRNA may act as "pawls" of a translocational ratchet. These findings provide new insights into the molecular mechanism of ribosomal translocation. Crystal structures of EF-G-ribosome complexes trapped in intermediate states of translocation.,Zhou J, Lancaster L, Donohue JP, Noller HF Science. 2013 Jun 28;340(6140):1236086. doi: 10.1126/science.1236086. PMID:23812722[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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