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Ribosomal protein

From Wikipedia, the free encyclopedia

A large ribosomal subunit (PDB:1FFK​).
A small ribosomal subunit (PDB:1FKA​).
The two ribosomal subunits. Proteins are shown in blue and the RNA chains in brown and yellow.

Aribosomal protein(r-proteinorrProtein[1][2][3]) is any of theproteinsthat, in conjunction withrRNA,make up theribosomalsubunits involved in the cellular process oftranslation.E. coli,other bacteria andArchaeahave a 30S small subunit and a 50S large subunit, whereas humans andyeastshave a 40S small subunit and a 60S large subunit.[4]Equivalent subunits are frequently numbered differently between bacteria, Archaea, yeasts and humans.[5]

A large part of the knowledge about these organic molecules has come from the study ofE. coliribosomes. All ribosomal proteins have been isolated and many specific antibodies have been produced. These, together withelectronic microscopyand the use of certain reactives, have allowed for the determination of the topography of the proteins in the ribosome. More recently, a near-complete (near)atomic picture of the ribosomal proteins is emerging from the latest high-resolution cryo-EM data (includingPDB:5AFI​).

Conservation

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A 2016tree of lifeusing 16 universally-conserved ribosomal protein sequences[6]

Ribosomal proteins are among the most highly conserved proteins across all life forms.[5]Among the 40 proteins found in varioussmall ribosomal subunits(RPSs), 15 subunits are universally conserved across prokaryotes and eukaryotes. However, 7 subunits are only found in bacteria (bS21, bS6, bS16, bS18, bS20, bS21, and bTHX), while 17 subunits are only found in archaea and eukaryotes.[5]Typically 22 proteins are found in bacterial small subunits and 32 in yeast, human and most likely most other eukaryotic species. Twenty-seven (out of 32) proteins of the eukaryotic small ribosomal subunit proteins are also present in archaea (no ribosomal protein is exclusively found in archaea), confirming that they are more closely related to eukaryotes than to bacteria.[5]

Among thelarge ribosomal subunit(RPLs), 18 proteins are universal, i.e. found in both bacteria, eukaryotes, and archaea. 14 proteins are only found in bacteria, while 27 proteins are only found in archaea and eukaryotes. Again, archaea have no proteins unique to them.[5]

Essentiality

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Despite their high conservation over billions of years of evolution, the absence of several ribosomal proteins in certain species shows that ribosomal subunits have been added and lost over the course of evolution. This is also reflected by the fact that several ribosomal proteins do not appear to be essential when deleted.[7]For instance, inE. colinine ribosomal proteins (uL15, bL21, uL24, bL27, uL29, uL30, bL34, uS9, and uS17) are nonessential for survival when deleted. Taken together with previous results, 22 of the 54E. coliribosomal protein genes can be individually deleted from the genome.[8]Similarly, 16 ribosomal proteins (uL1, bL9, uL15, uL22, uL23, bL28, uL29, bL32, bL33.1, bL33.2, bL34, bL35, bL36, bS6, bS20, and bS21) were successfully deleted inBacillus subtilis.In conjunction with previous reports, 22 ribosomal proteins have been shown to be nonessential inB. subtilis,at least for cell proliferation.[9]

Assembly

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InE. coli

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The ribosome ofE. colihas about 22 proteins in the small subunit (labelled S1 to S22) and 33 proteins in the large subunit (somewhat counter-intuitively called L1 to L36). All of them are different with three exceptions: one protein is found in both subunits (S20 and L26),[dubiousdiscuss]L7 and L12 are acetylated and methylated forms of the same protein, and L8 is a complex of L7/L12 and L10. In addition, L31 is known to exist in two forms, the full length at 7.9 kilodaltons (kDa) and fragmented at 7.0 kDa. This is why the number of proteins in a ribosome is of 56. Except for S1 (with a molecular weight of 61.2 kDa), the other proteins range in weight between 4.4 and 29.7 kDa.[10]

Recentde novoproteomics experiments where the authors characterizedin vivoribosome-assembly intermediates and associated assembly factors from wild-typeEscherichia colicells using a general quantitative mass spectrometry (qMS) approach have confirmed the presence of all the known small and large subunit components and have identified a total of 21 known and potentially new ribosome-assembly-factors that co-localise with various ribosomal particles.[11]

Disposition in the small ribosomal subunit

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In the small (30S) subunit ofE. coliribosomes, the proteins denoted uS4, uS7, uS8, uS15, uS17, bS20 bind independently to 16S rRNA. After assembly of these primary binding proteins, uS5, bS6, uS9, uS12, uS13, bS16, bS18, and uS19 bind to the growing ribosome. These proteins also potentiate the addition of uS2, uS3, uS10, uS11, uS14, and bS21. Protein binding to helical junctions is important for initiating the correct tertiary fold of RNA and to organize the overall structure. Nearly all the proteins contain one or more globular domains. Moreover, nearly all contain long extensions that can contact the RNA in far-reaching regions.[citation needed]Additional stabilization results from the proteins' basic residues, as these neutralize the charge repulsion of the RNA backbone. Protein–protein interactions also exist to hold structure together by electrostatic and hydrogen bonding interactions. Theoretical investigations pointed to correlated effects of protein-binding onto binding affinities during the assembly process[12]

In one study, the net charges (at pH 7.4) of the ribosomal proteins comprising the highly conserved S10-spc cluster were found to have an inverse relationship with the halophilicity/halotolerance levels in bacteria and archaea.[13]In non-halophilic bacteria, the S10-spc proteins are generally basic, contrasting with the overall acidic whole proteomes of the extremely halophiles. The universal uL2 lying in the oldest part of the ribosome, is always positively charged irrespective of the strain/organism it belongs to.[13]

In eukaryotes

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Ribosomes in eukaryotes contain 79–80 proteins and four ribosomal RNA (rRNA) molecules. General or specializedchaperonessolubilizethe ribosomal proteins and facilitate their import into thenucleus.Assembly of the eukaryotic ribosome appears to be driven by the ribosomal proteins in vivo when assembly is also aided by chaperones. Most ribosomal proteins assemble with rRNA co-transcriptionally, becoming associated more stably as assembly proceeds, and the active sites of both subunits are constructed last.[5]

Table of ribosomal proteins

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In the past, different nomenclatures were used for the same ribosomal protein in different organisms. Not only were the names not consistent across domains; the names also differed between organisms within a domain, such as humans andS. cervisiae,both eukaryotes. This was due to researchers assigning names before the sequences were known, causing trouble for later research. The following tables use the unified nomenclature by Ban et al., 2014. The same nomenclature is used byUniProt's "family" curation.[5]

In general, cellular ribosomal proteins are to be called simply using the cross domain name, e.g. "uL14" for what is currently called L23 in humans. A suffix is used for the organellar versions, so that "uL14m" refers to the human mitochondrial uL14 (MRPL14).[5]Organelle-specific proteins use their own cross-domain prefixes, for example "mS33" forMRPS33[14]: Table S3,S4 and "cL37" for PSRP5.[15]: Table S2,S3 (See the two proceeding citations, also partially by Ban N, for the organelle nomenclatures.)

Small subunit ribosomal proteins[5]
Cross-domain name[a] Pfam domain Taxonomic range[b] Bacteria name (E. coliUniProt) Yeast name Human name
bS1 PF00575 B S1P0AG67
eS1 PF01015 A E S1 S3A
uS2 PF00318,PF16122 B A E S2P0A7V0 S0 SA
uS3 PF00189,PF07650 B A E S3P0A7V3 S3 S3
uS4 PF00163,PF01479 B A E S4P0A7V8 S9 S9
eS4 PF00900,PF08071,PF16121 A E S4 S4 (X,Y1,Y2)
uS5 PF00333,PF03719 B A E S5P0A7W1 S2 S2
bS6 PF01250 B S6P02358
eS6 PF01092 A E S6 S6
uS7 PF00177 B A E S7P02359 S5 S5
eS7 PF01251 E S7 S7
uS8 PF00410 B A E S8P0A7W7 S22 S15A
eS8 PF01201 A E S8 S8
uS9 PF00380 B A E S9P0A7X3 S16 S16
uS10 PF00338 B A E S10P0A7R5 S20 S20
eS10 PF03501 E S10 S10
uS11 PF00411 B A E S11P0A7R9 S14 S14
uS12 PF00164 B A E S12P0A7S3 S23 S23
eS12 PF01248 E S12 S12
uS13 PF00416 B A E S13P0A7S9 S18 S18
uS14 PF00253 B A E S14P0AG59 S29 S29
uS15 PF00312 B A E S15P0ADZ4 S13 S13
bS16 PF00886 B S16P0A7T3
uS17 PF00366 B A E S17P0AG63 S11 S11
eS17 PF00366 A E S17 S17
bS18 PF01084 B S18P0A7T7
uS19 PF00203 B A E S19P0A7U3 S15 S15
eS19 PF01090 A E S19 S19
bS20 PF01649 B S20P0A7U7
bS21 PF01165 B S21P68681
bTHX PF17070,PF17067 B THX (missing fromE. coli)
eS21 PF01249 E S21 S21
eS24 PF01282 A E S24 S24
eS25 PF03297 A E S25 S25
eS26 PF01283 E S26 S26
eS27 PF01667 A E S27 S27
eS28 PF01200 A E S28 S28
eS30 PF04758 A E S30 S30
eS31 PF01599 A E S31 S27A
RACK1 PF00400 E Asc1 RACK1
Large subunit ribosomal proteins[5]
Cross-domain name[a] Pfam domains Taxonomic range[b] Bacteria name (E. coliUniProt) Yeast name Human name
uL1 PF00687 B A E L1P0A7L0 L1 L10A
uL2 PF03947,PF00181 B A E L2P60422 L2 L8
uL3 PF00297 B A E L3P60438 L3 L3
uL4 PF00573 B A E L4P60723 L4 L4
uL5 PF00281,PF00673(b) B A E L5P62399 L11 L11
uL6 PF00347 B A E L6P0AG55 L9 L9
eL6 PF01159,PF03868 E L6 L6
eL8 PF01248 A E L8 L7A
bL9 PF01281,PF03948 B L9P0A7R1
uL10 PF00466 B A E L10P0A7J3 P0 P0
uL11 PF03946,PF00298 B A E L11P0A7J7 L12 L12
bL12 PF16320,PF00542 B L7/L12P0A7K2
uL13 PF00572 B A E L13P0AA10 L16 L13A
eL13 PF01294 A E L13 L13
uL14 PF00238 B A E L14P0ADY3 L23 L23
eL14 PF01929 A E L14 L14
uL15 PF00828 B A E L15P02413 L28 L27A
eL15 PF00827 A E L15 L15
uL16 PF00252 B A E L16P0ADY7 L10 L10
bL17 PF01196 B L17P0AG44
uL18 PF00861 B A E L18P0C018 L5 L5
eL18 PF00828 A E L18 L18
bL19 PF01245 B L19B1LPB3
eL19 PF01280 A E L19 L19
bL20 PF00453 B L20P0A7L3
eL20 PF01775 E L20 L18A
bL21 PF00829 B L21P0AG48
eL21 PF01157 A E L21 L21
uL22 PF00237 B A E L22P61175 L17 L17
eL22 PF01776 E L22 L22
uL23 PF00276,PF03939(e) B A E L23P0ADZ0 L25 L23A
uL24 PF00467(b),PF16906(ae) B A E L24P60624 L26 L26
eL24 PF01246 A E L24 L24
bL25 PF01386 B L25P68919
bL27 PF01016 B L27P0A7M0
eL27 PF01777 E L27 L27
bL28 PF00830 B L28P0A7M2
eL28 PF01778 E L28
uL29 PF00831 B A E L29P0A7M6 L35 L35
eL29 PF01779 E L29 L29
uL30 PF00327 B A E L30P0AG51 L7 L7
eL30 PF01248 A E L30 L30
bL31 PF01197 B L31P0A7M9
eL31 PF01198 A E L31 L31
bL32 PF01783 B L32C4ZS29
eL32 PF01655 A E L32 L32
bL33 PF00471 B L33P0A7N9
eL33 PF01247 A E L33 L35A
bL34 PF00468 B L34P0A7P6
eL34 PF01199 A E L34 L34
bL35 PF01632 B L35P0A7Q2
bL36 PF00444 B L36P0A7Q7
eL36 PF01158 E L36 L36
eL37 PF01907 A E L37 L37
eL38 PF01781 A E L38 L38
eL39 PF00832 A E L39 L39
eL40 PF01020 A E L40 L40
eL41 PF05162 A E L41 L41
eL42 PF00935 A E L42 L36A
eL43 PF01780 A E L43 L37A
P1/P2 PF00428 A E P1/P2 (AB) P1/P2(αβ)
  1. ^abb = bacteria (+organelle); e = eukarya cytoplasm; u = universal. Older nomenclature often have the order reversed, so that "bS1" becomes S1b or S1p (for "prokaryote" ).
  2. ^abB = bacteria (+organelle); A = archaea; E = eukarya cytoplasm

See also

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References

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  1. ^Salini Konikkat:Dynamic Remodeling Events Drive the Removal of the ITS2 Spacer Sequence During Assembly of 60S Ribosomal Subunits in S. cerevisiae.Carnegie Mellon University Dissertations, Feb. 2016.
  2. ^Weiler EW, Nover L (2008).Allgemeine und molekulare Botanik(in German). Stuttgart: Georg Thieme Verlag. p. 532.ISBN978-3-13-152791-2.
  3. ^de la Cruz J, Karbstein K, Woolford JL (2015)."Functions of ribosomal proteins in assembly of eukaryotic ribosomes in vivo".Annual Review of Biochemistry(in German).84:93–129.doi:10.1146/annurev-biochem-060614-033917.PMC4772166.PMID25706898.
  4. ^Rodnina MV, Wintermeyer W (April 2011). "The ribosome as a molecular machine: the mechanism of tRNA-mRNA movement in translocation".Biochemical Society Transactions.39(2): 658–62.doi:10.1042/BST0390658.PMID21428957.
  5. ^abcdefghijBan N, Beckmann R, Cate JH, Dinman JD, Dragon F, Ellis SR, et al. (February 2014)."A new system for naming ribosomal proteins".Current Opinion in Structural Biology.24:165–9.doi:10.1016/j.sbi.2014.01.002.PMC4358319.PMID24524803.
  6. ^Hug LA, Baker BJ, Anantharaman K, Brown CT, Probst AJ, Castelle CJ, et al. (April 2016)."A new view of the tree of life".Nature Microbiology.1(5): 16048.doi:10.1038/nmicrobiol.2016.48.PMID27572647.
  7. ^Gao F, Luo H, Zhang CT, Zhang R (2015). "Gene Essentiality Analysis Based on DEG 10, an Updated Database of Essential Genes".Gene Essentiality.Methods in Molecular Biology. Vol. 1279. pp. 219–33.doi:10.1007/978-1-4939-2398-4_14.ISBN978-1-4939-2397-7.PMID25636622.
  8. ^Shoji S, Dambacher CM, Shajani Z, Williamson JR, Schultz PG (November 2011)."Systematic chromosomal deletion of bacterial ribosomal protein genes".Journal of Molecular Biology.413(4): 751–61.doi:10.1016/j.jmb.2011.09.004.PMC3694390.PMID21945294.
  9. ^Akanuma G, Nanamiya H, Natori Y, Yano K, Suzuki S, Omata S, et al. (November 2012)."Inactivation of ribosomal protein genes in Bacillus subtilis reveals importance of each ribosomal protein for cell proliferation and cell differentiation".Journal of Bacteriology.194(22): 6282–91.doi:10.1128/JB.01544-12.PMC3486396.PMID23002217.
  10. ^Arnold RJ, Reilly JP (April 1999). "Observation of Escherichia coli ribosomal proteins and their posttranslational modifications by mass spectrometry".Analytical Biochemistry.269(1): 105–12.doi:10.1006/abio.1998.3077.PMID10094780.
  11. ^Chen SS, Williamson JR (February 2013)."Characterization of the ribosome biogenesis landscape in E. coli using quantitative mass spectrometry".Journal of Molecular Biology.425(4): 767–79.doi:10.1016/j.jmb.2012.11.040.PMC3568210.PMID23228329.
  12. ^Hamacher K, Trylska J, McCammon JA (February 2006)."Dependency map of proteins in the small ribosomal subunit".PLOS Computational Biology.2(2): e10.Bibcode:2006PLSCB...2...10H.doi:10.1371/journal.pcbi.0020010.PMC1364506.PMID16485038.
  13. ^abTirumalai MR, Anane-Bediakoh D, Rajesh R, Fox GE (November 2021)."Net Charges of the Ribosomal Proteins of theS10andspcClusters of Halophiles Are Inversely Related to the Degree of Halotolerance ".Microbiol. Spectr.9(3): e0178221.doi:10.1128/spectrum.01782-21.PMC8672879.PMID34908470.
  14. ^Greber BJ, Bieri P, Leibundgut M, Leitner A, Aebersold R, Boehringer D, Ban N (April 2015). "Ribosome. The complete structure of the 55S mammalian mitochondrial ribosome".Science.348(6232): 303–8.doi:10.1126/science.aaa3872.hdl:20.500.11850/100390.PMID25837512.S2CID206634178.
  15. ^Bieri, P; Leibundgut, M; Saurer, M; Boehringer, D; Ban, N (15 February 2017)."The complete structure of the chloroplast 70S ribosome in complex with translation factor pY".The EMBO Journal.36(4): 475–486.doi:10.15252/embj.201695959.PMC5694952.PMID28007896.

Further reading

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