3j00 | pdb_00003j00

Structure of the ribosome-SecYE complex in the membrane environment

spinqualitylabelsall models 3j00, resolution 7.10Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3j00 is a 26 chain structure with sequence from Eco57, Ecoli, Escherichia coli and Escherichia coli dh1. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: PEV, PGV Related: 3j01 Resources: FirstGlance, OCA, RCSB, PDBsum Disease [APOA1_HUMAN] Defects in APOA1 are a cause of high density lipoprotein deficiency type 2 (HDLD2) [MIM:604091]; also known as familial hypoalphalipoproteinemia (FHA). Inheritance is autosomal dominant. Defects in APOA1 are a cause of the low HDL levels observed in high density lipoprotein deficiency type 1 (HDLD1) [MIM:205400]; also known as analphalipoproteinemia or Tangier disease (TGD). HDLD1 is a recessive disorder characterized by the absence of plasma HDL, accumulation of cholesteryl esters, premature coronary artery disease, hepatosplenomegaly, recurrent peripheral neuropathy and progressive muscle wasting and weakness. In HDLD1 patients, ApoA-I fails to associate with HDL probably because of the faulty conversion of pro-ApoA-I molecules into mature chains, either due to a defect in the converting enzyme activity or a specific structural defect in Tangier ApoA-I. Note=A mutation in APOA1 is the cause of amyloid polyneuropathy-nephropathy Iowa type (AMYLIOWA); also known as amyloidosis van Allen type or familial amyloid polyneuropathy type III. AMYLIOWA is a hereditary generalized amyloidosis due to deposition of amyloid mainly constituted by apolipoprotein A1. The clinical picture is dominated by neuropathy in the early stages of the disease and nephropathy late in the course. Death is due in most cases to renal amyloidosis. Severe peptic ulcer disease can occurr in some and hearing loss is frequent. Cataracts is present in several, but vitreous opacities are not observed. Defects in APOA1 are a cause of amyloidosis type 8 (AMYL8) [MIM:105200]; also known as systemic non-neuropathic amyloidosis or Ostertag-type amyloidosis. AMYL8 is a hereditary generalized amyloidosis due to deposition of apolipoprotein A1, fibrinogen and lysozyme amyloids. Viscera are particularly affected. There is no involvement of the nervous system. Clinical features include renal amyloidosis resulting in nephrotic syndrome, arterial hypertension, hepatosplenomegaly, cholestasis, petechial skin rash. Function [RS7_ECOLI] 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. Is located at the subunit interface close to the decoding center, where it has been shown to contact mRNA. Has been shown to contact tRNA in both the P and E sites; it probably blocks exit of the E site tRNA. Protein S7 is also a translational repressor protein; it regulates the expression of the str operon members to different degrees by binding to its mRNA. [RS17_ECOLI] One of the primary rRNA binding proteins, it binds specifically to the 5'-end of 16S ribosomal RNA. Also plays a role in translational accuracy; neamine-resistant ribosomes show reduced neamine-induced misreading in vitro.[HAMAP-Rule:MF_01345] [RS3_ECOLI] Binds the lower part of the 30S subunit head. Binds mRNA in the 70S ribosome, positioning it for translation (By similarity). Plays a role in mRNA unwinding by the ribosome, possibly by forming part of a processivity clamp. [RS13_ECOLI] Located at the top of the head of the 30S subunit, it contacts several helices of the 16S rRNA. In the E.coli 70S ribosome in the initiation state (PubMed:12809609) was modeled to contact the 23S rRNA (bridge B1a) and protein L5 of the 50S subunit (bridge B1b), connecting the 2 subunits; bridge B1a is broken in the model with bound EF-G, while the protein-protein contacts between S13 and L5 in B1b change (PubMed:12809609). The 23S rRNA contact site in bridge B1a is modeled to differ in different ribosomal states (PubMed:16272117), contacting alternately S13 or S19. In the two 3.5 angstroms resolved ribosome structures (PubMed:12859903) the contacts between L5, S13 and S19 bridge B1b are different, confirming the dynamic nature of this interaction. Bridge B1a is not visible in the crystallized ribosomes due to 23S rRNA disorder. Contacts the tRNAs in the A and P sites. The C-terminal tail plays a role in the affinity of the 30S P site for different tRNAs. [RS18_ECOLI] Binds as a heterodimer with protein S6 to the central domain of the 16S rRNA, where it helps stabilize the platform of the 30S subunit.[HAMAP-Rule:MF_00270] [RS14_ECOLI] Binds 16S rRNA, required for the assembly of 30S particles and may also be responsible for determining the conformation of the 16S rRNA at the A site.[HAMAP-Rule:MF_00537] [RS19_ECOLI] In the E.coli 70S ribosome in the initiation state (PubMed:12809609) it has been modeled to contact the 23S rRNA of the 50S subunit forming part of bridge B1a; this bridge is broken in the model with bound EF-G. The 23S rRNA contact site in bridge B1a is modeled to differ in different ribosomal states (PubMed:12859903), contacting alternately S13 or S19. In the 3.5 angstroms resolved ribosome structures (PubMed:16272117) the contacts between L5, S13 and S19 bridge B1b are different, confirming the dynamic nature of this interaction. Bridge B1a is not visible in the crystallized ribosomes due to 23S rRNA disorder.[HAMAP-Rule:MF_00531] Protein S19 forms a complex with S13 that binds strongly to the 16S ribosomal RNA. Contacts the A site tRNA.[HAMAP-Rule:MF_00531] [RS9_ECOLI] The C-terminal tail plays a role in the affinity of the 30S P site for different tRNAs. Mutations that decrease this affinity are suppressed in the 70S ribosome. [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] [RS5_ECOLI] With S4 and S12 plays an important role in translational accuracy. Many suppressors of streptomycin-dependent mutants of protein S12 are found in this protein, some but not all of which decrease translational accuracy (ram, ribosomal ambiguity mutations). Located at the back of the 30S subunit body where it stabilizes the conformation of the head with respect to the body. The physical location of this protein suggests it may also play a role in mRNA unwinding by the ribosome, possibly by forming part of a processivity clamp. [RS8_ECOLI] 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_B] Protein S8 is a translational repressor protein, it controls the translation of the spc operon by binding to its mRNA.[HAMAP-Rule:MF_01302_B] [RS10_ECOLI] Involved in the binding of tRNA to the ribosomes.[HAMAP-Rule:MF_00508] [RS11_ECOLI] Located on the platform of the 30S subunit, it bridges several disparate RNA helices of the 16S rRNA. Forms part of the Shine-Dalgarno cleft in the 70S ribosome (By similarity).[HAMAP-Rule:MF_01310] [RS16_ECOLI] In addition to being a ribosomal protein, S16 also has a cation-dependent endonuclease activity. In-frame fusions with the ribosome maturation factor rimM suppress mutations in the latter (probably due to increased rimM expression) and are found in translationally active 70S ribosomes. [RS4_ECOLI] One of two assembly initiator proteins for the 30S subunit, it binds directly to 16S rRNA where it nucleates assembly of the body of the 30S subunit. With S5 and S12 plays an important role in translational accuracy; many suppressors of streptomycin-dependent mutants of protein S12 are found in this protein, some but not all of which decrease translational accuracy (ram, ribosomal ambiguity mutations). Plays a role in mRNA unwinding by the ribosome, possibly by forming part of a processivity clamp. Protein S4 is also a translational repressor protein, it controls the translation of the alpha-operon (which codes for S13, S11, S4, RNA polymerase alpha subunit, and L17) by binding to its mRNA. Also functions as a rho-dependent antiterminator of rRNA transcription, increasing the synthesis of rRNA under conditions of excess protein, allowing a more rapid return to homeostasis. Binds directly to RNA polymerase. [Q8X9Y5_ECO57] Essential cell division protein. May link together the upstream cell division proteins, which are predominantly cytoplasmic, with the downstream cell division proteins, which are predominantly periplasmic. May control correct divisome assembly (By similarity).[HAMAP-Rule:MF_00911] [RS20_ECOLI] Binds directly to 16S ribosomal RNA.[HAMAP-Rule:MF_00500] [RS6_ECOLI] Binds together with S18 to 16S ribosomal RNA.[HAMAP-Rule:MF_00360] [RS15_ECOLI] One of the primary rRNA binding proteins, it binds directly to 16S rRNA where it helps nucleate assembly of the platform of the 30S subunit by binding and bridging several RNA helices of the 16S rRNA.[HAMAP-Rule:MF_01343] In the E.coli 70S ribosome it has been modeled (PubMed:12809609) to contact the 23S rRNA of the 50S subunit forming part of bridge B4. In the two 3.5 A resolved ribosome structures (PubMed:16272117) there are minor differences between side-chain conformations.[HAMAP-Rule:MF_01343] [APOA1_HUMAN] Participates in the reverse transport of cholesterol from tissues to the liver for excretion by promoting cholesterol efflux from tissues and by acting as a cofactor for the lecithin cholesterol acyltransferase (LCAT). As part of the SPAP complex, activates spermatozoa motility. Publication Abstract from PubMed The ubiquitous SecY-Sec61 complex translocates nascent secretory proteins across cellular membranes and integrates membrane proteins into lipid bilayers. Several structures of mostly detergent-solubilized Sec complexes have been reported. Here we present a single-particle cryo-EM structure of the SecYEG complex in a membrane environment, bound to a translating ribosome, at subnanometer resolution. Using the SecYEG complex reconstituted in a so-called Nanodisc, we could trace the nascent polypeptide chain from the peptidyltransferase center into the membrane. The reconstruction allowed for the identification of ribosome-lipid interactions. The rRNA helix 59 (H59) directly contacts the lipid surface and appears to modulate the membrane in immediate vicinity to the proposed lateral gate of the protein-conducting channel (PCC). On the basis of our map and molecular dynamics simulations, we present a model of a signal anchor-gated PCC in the membrane. Cryo-EM structure of the ribosome-SecYE complex in the membrane environment.,Frauenfeld J, Gumbart J, Sluis EO, Funes S, Gartmann M, Beatrix B, Mielke T, Berninghausen O, Becker T, Schulten K, Beckmann R Nat Struct Mol Biol. 2011 May;18(5):614-21. Epub 2011 Apr 17. PMID:21499241 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Ribosome 3D structures

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