4v9k
70S ribosome translocation intermediate GDPNP-I containing elongation factor EFG/GDPNP, mRNA, and tRNA bound in the pe*/E state.70S ribosome translocation intermediate GDPNP-I containing elongation factor EFG/GDPNP, mRNA, and tRNA bound in the pe*/E state.
Structural highlights
FunctionRL20_THET2 Binds directly to 23S ribosomal RNA and is necessary for the in vitro assembly process of the 50S ribosomal subunit. It is not involved in the protein synthesizing functions of that subunit (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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