6eri
Structure of the chloroplast ribosome with chl-RRF and hibernation-promoting factor
Structural highlights
Function[RRFC_SPIOL] Responsible for the release of ribosomes from messenger RNA at the termination of chloroplastic protein biosynthesis. [RK27_SPIOL] Component of the chloroplast ribosome (chloro-ribosome), a dedicated translation machinery responsible for the synthesis of chloroplast genome-encoded proteins, including proteins of the transcription and translation machinery and components of the photosynthetic apparatus.[1] [2] [RK6_SPIOL] Component of the chloroplast ribosome (chloro-ribosome), a dedicated translation machinery responsible for the synthesis of chloroplast genome-encoded proteins, including proteins of the transcription and translation machinery and components of the photosynthetic apparatus.[3] [4] [RK21_SPIOL] This protein binds to 23S ribosomal RNA in the presence of protein L20 (By similarity). [RK22_SPIOL] This protein binds specifically to 23S rRNA (By similarity). The globular domain of the protein is located near the polypeptide exit tunnel on the outside of the subunit, while an extended beta-hairpin is found that lines the wall of the exit tunnel in the center of the 70S ribosome (By similarity). Binds an erythromycin derivative added to the 50S subunit. [RK20_SPIOL] 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).[HAMAP-Rule:MF_00382] [PRSP1_SPIOL] A ribosome-binding factor that may be involved in an unknown stress response. Modeling onto the 70S spinach chloroplast ribosome and its position in the E.coli 70S ribosome suggests it binds in the decoding region of the 30S ribosomal subunit, precluding the binding of tRNA to the ribosome. Its position is incompatible with translation. Upon expression in E.coli binds to 30S and 70S ribosomes, decreases binding of tRNA(fMet). Stabilizes 70S ribosomes against dissociation. May be recycled by the combined action of ribosome-recycling factor (RRF) and EF-G.[5] [RK34_SPIOL] This protein binds directly to 23S ribosomal RNA (By similarity). [RR7_SPIOL] One of the primary rRNA binding proteins, it binds directly to 16S rRNA where it nucleates assembly of the head domain of the 30S subunit (By similarity).[HAMAP-Rule:MF_00480] [RK18_SPIOL] Component of the chloroplast ribosome (chloro-ribosome), a dedicated translation machinery responsible for the synthesis of chloroplast genome-encoded proteins, including proteins of the transcription and translation machinery and components of the photosynthetic apparatus.[6] [7] [RK24_SPIOL] One of two assembly initiator proteins, it binds directly to the 5'-end of the 23S rRNA, where it nucleates assembly of the 50S subunit (By similarity). Located at the polypeptide exit tunnel on the outside of the subunit. [RK31_SPIOL] Component of the chloroplast ribosome (chloro-ribosome), a dedicated translation machinery responsible for the synthesis of chloroplast genome-encoded proteins, including proteins of the transcription and translation machinery and components of the photosynthetic apparatus.[8] [9] [RK14_SPIOL] Binds to 23S rRNA (By similarity). [RK15_SPIOL] Component of the chloroplast ribosome (chloro-ribosome), a dedicated translation machinery responsible for the synthesis of chloroplast genome-encoded proteins, including proteins of the transcription and translation machinery and components of the photosynthetic apparatus.[10] [11] [RR20_SPIOL] Component of the chloroplast ribosome (chloro-ribosome), a dedicated translation machinery responsible for the synthesis of chloroplast genome-encoded proteins, including proteins of the transcription and translation machinery and components of the photosynthetic apparatus.[12] [13] [RR9_SPIOL] Binds directly to 16S ribosomal RNA.[14] [:] [RK28_SPIOL] Component of the chloroplast ribosome (chloro-ribosome), a dedicated translation machinery responsible for the synthesis of chloroplast genome-encoded proteins, including proteins of the transcription and translation machinery and components of the photosynthetic apparatus.[15] [16] [RR13_SPIOL] Located at the top of the head of the 30S subunit, it contacts several helices of the 16S rRNA.[HAMAP-Rule:MF_01315] [RK17_SPIOL] Component of the chloroplast ribosome (chloro-ribosome), a dedicated translation machinery responsible for the synthesis of chloroplast genome-encoded proteins, including proteins of the transcription and translation machinery and components of the photosynthetic apparatus.[17] [18] [RK29_SPIOL] Component of the chloroplast ribosome (chloro-ribosome), a dedicated translation machinery responsible for the synthesis of chloroplast genome-encoded proteins, including proteins of the transcription and translation machinery and components of the photosynthetic apparatus.[19] [20] [RK5_SPIOL] Binds 5S rRNA, forms part of the central protuberance of the 50S subunit (By similarity). [RR17_SPIOL] Component of the chloroplast ribosome (chloro-ribosome), a dedicated translation machinery responsible for the synthesis of chloroplast genome-encoded proteins, including proteins of the transcription and translation machinery and components of the photosynthetic apparatus.[21] [22] [RR6_SPIOL] Binds together with S18 to 16S ribosomal RNA (By similarity).[UniProtKB:O78447] [RR8_SPIOL] One of the primary rRNA binding proteins, it binds directly to 16S rRNA central domain where it helps coordinate assembly of the platform of the 30S subunit (By similarity).[HAMAP-Rule:MF_01302] [RR14_SPIOL] Binds 16S rRNA, required for the assembly of 30S particles (By similarity).[:] [RK19_SPIOL] Located at the 30S-50S ribosomal subunit interface and binds directly to 23S ribosomal RNA (By similarity).[:] [RK9_SPIOL] Component of the chloroplast ribosome (chloro-ribosome), a dedicated translation machinery responsible for the synthesis of chloroplast genome-encoded proteins, including proteins of the transcription and translation machinery and components of the photosynthetic apparatus.[23] [24] [RR19_SPIOL] This protein binds directly to 16S ribosomal RNA.[25] [RR5_SPIOL] Binds directly to 16S ribosomal RNA. Involved in spectinomycin and neamine resistance and streptomycin independence.[:] [RK3_SPIOL] Component of the chloroplast ribosome (chloro-ribosome), a dedicated translation machinery responsible for the synthesis of chloroplast genome-encoded proteins, including proteins of the transcription and translation machinery and components of the photosynthetic apparatus.[26] [27] [RR12_SPIOL] With S4 and S5 plays an important role in translational accuracy. Located at the interface of the 30S and 50S subunits (By similarity).[HAMAP-Rule:MF_00403_B] [RR4_SPIOL] One of the primary rRNA binding proteins, it binds directly to 16S rRNA where it nucleates assembly of the body of the 30S subunit (By similarity).[HAMAP-Rule:MF_01306] With S5 and S12 plays an important role in translational accuracy (By similarity).[HAMAP-Rule:MF_01306] [RR10_SPIOL] Component of the chloroplast ribosome (chloro-ribosome), a dedicated translation machinery responsible for the synthesis of chloroplast genome-encoded proteins, including proteins of the transcription and translation machinery and components of the photosynthetic apparatus.[28] [29] [RK23_SPIOL] Binds to 23S rRNA (By similarity). Located at the polypeptide exit tunnel on the outside of the subunit. [RR21_SPIOL] Component of the chloroplast ribosome (chloro-ribosome), a dedicated translation machinery responsible for the synthesis of chloroplast genome-encoded proteins, including proteins of the transcription and translation machinery and components of the photosynthetic apparatus.[30] [31] [RK4_SPIOL] Probably binds the 23S rRNA (By similarity). This protein (expressed without the transit peptide) is able to provoke transcription termination from the spinach chloroplast rDNA operon and the E.coli S10 operon in vitro. Publication Abstract from PubMedOxygenic photosynthesis produces oxygen and builds a variety of organic compounds, changing the chemistry of the air, the sea and fuelling the food chain on our planet. The photochemical reactions underpinning this process in plants take place in the chloroplast. Chloroplasts evolved ~1.2 billion years ago from an engulfed primordial diazotrophic cyanobacterium, and chlororibosomes are responsible for synthesis of the core proteins driving photochemical reactions. Chlororibosomal activity is spatiotemporally coupled to the synthesis and incorporation of functionally essential co-factors, implying the presence of chloroplast-specific regulatory mechanisms and structural adaptation of the chlororibosome(1,2). Despite recent structural information(3-6), some of these aspects remained elusive. To provide new insights into the structural specialities and evolution, we report a comprehensive analysis of the 2.9-3.1 A resolution electron cryo-microscopy structure of the spinach chlororibosome in complex with its recycling factor and hibernation-promoting factor. The model reveals a prominent channel extending from the exit tunnel to the chlororibosome exterior, structural re-arrangements that lead to increased surface area for translocon binding, and experimental evidence for parallel and convergent evolution of chloro- and mitoribosomes. Structure of the chloroplast ribosome with chl-RRF and hibernation-promoting factor.,Boerema AP, Aibara S, Paul B, Tobiasson V, Kimanius D, Forsberg BO, Wallden K, Lindahl E, Amunts A Nat Plants. 2018 Apr;4(4):212-217. doi: 10.1038/s41477-018-0129-6. Epub 2018 Apr , 2. PMID:29610536[32] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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