Editing Ribosome (section)

== Origin ==
The ribosome may have first originated as a protoribosome,<ref name="Dance-2023">{{cite journal |last=Dance |first=Amber |title=How did life begin? One key ingredient is coming into view - A Nobel-prizewinning scientist's team has taken a big step forward in its quest to reconstruct an early-Earth RNA capable of building proteins. |date=28 February 2023 |journal=[[Nature (journal)|Nature]] |volume=615 |issue=7950 |pages=22–25 |doi=10.1038/d41586-023-00574-4 |pmid=36854922 |doi-access=free }}</ref> possibly containing a peptidyl transferase centre (PTC), in an [[RNA world]], appearing as a self-replicating complex that only later evolved the ability to synthesize proteins when [[amino acid]]s began to appear.<ref name="Noller-2012">{{cite journal | vauthors = Noller HF | title = Evolution of protein synthesis from an RNA world | journal = Cold Spring Harbor Perspectives in Biology | volume = 4 | issue = 4 | pages = a003681 | date = April 2012 | pmid = 20610545 | pmc = 3312679 | doi = 10.1101/cshperspect.a003681 }}</ref> Studies suggest that ancient ribosomes constructed solely of [[Ribosomal RNA|rRNA]] could have developed the ability to synthesize [[peptide bond]]s.<ref>{{cite book | vauthors = Dabbs ER | date = 1986 | title = Mutant studies on the prokaryotic ribosome. | publisher = Springer-Verlag | location = New York }}</ref><ref>{{cite journal | vauthors = Noller HF, Hoffarth V, Zimniak L | title = Unusual resistance of peptidyl transferase to protein extraction procedures | journal = Science | volume = 256 | issue = 5062 | pages = 1416–9 | date = June 1992 | pmid = 1604315 | doi = 10.1126/science.1604315 | bibcode = 1992Sci...256.1416N }}</ref><ref>{{cite journal | vauthors = Nomura M, Mizushima S, Ozaki M, Traub P, Lowry CV | title = Structure and function of ribosomes and their molecular components | journal = Cold Spring Harbor Symposia on Quantitative Biology | volume = 34 | pages = 49–61 | year = 1969 | pmid = 4909519 | doi = 10.1101/sqb.1969.034.01.009 }}</ref><ref name="Krupkin-2011">{{cite journal | vauthors = Krupkin M, Matzov D, Tang H, Metz M, Kalaora R, Belousoff MJ, Zimmerman E, Bashan A, Yonath A | title = A vestige of a prebiotic bonding machine is functioning within the contemporary ribosome | journal = Phil. Trans. R. Soc. B | volume = 366 | issue = 1580 | pages = 2972–8 | date = Oct 2011 | pmid = 21930590 | doi = 10.1098/rstb.2011.0146 | pmc = 3158926 }}</ref><ref name="Bose-2022">{{cite journal | vauthors = Bose T, Fridkin G, Davidovich C, Krupkin M, Dinger N, Falkovich AH, Peleg Y, Agmon I, Bashan A, Yonat A | title = Origin of life: protoribosome forms peptide bonds and links RNA and protein dominated worlds | journal = Nucleic Acids Res | volume = 50 | issue = 4 | pages = 1815–1828 | date = Feb 2022 | pmid = 35137169 | doi = 10.1093/nar/gkac052 | pmc = 8886871 }}</ref> In addition, evidence strongly points to ancient ribosomes as self-replicating complexes, where the rRNA in the ribosomes had informational, structural, and catalytic purposes because it could have coded for [[Transfer RNA|tRNAs]] and proteins needed for ribosomal self-replication.<ref name="Root-Bernstein-2015">{{cite journal | vauthors = Root-Bernstein M, Root-Bernstein R | title = The ribosome as a missing link in the evolution of life | journal = Journal of Theoretical Biology | volume = 367 | pages = 130–158 | date = February 2015 | pmid = 25500179 | doi = 10.1016/j.jtbi.2014.11.025 | doi-access = free }}</ref> Hypothetical cellular organisms with self-replicating RNA but without DNA are called [[ribocyte]]s (or ribocells).<ref name="Yarus-2002">{{cite journal | vauthors = Yarus M | title = Primordial genetics: phenotype of the ribocyte | journal = Annual Review of Genetics | volume = 36 | pages = 125–51 | year = 2002 | pmid = 12429689 | doi = 10.1146/annurev.genet.36.031902.105056 }}</ref><ref>{{cite book | doi=10.1007/978-94-007-4899-6_3|chapter = The Origin of Virions and Virocells: The Escape Hypothesis Revisited|title = Viruses: Essential Agents of Life| pages=43–60|year = 2012| vauthors = Forterre P, Krupovic M | isbn=978-94-007-4898-9}}</ref>

As amino acids gradually appeared in the RNA world under prebiotic conditions,<ref>{{cite journal | vauthors = Caetano-Anollés G, Seufferheld MJ | title = The coevolutionary roots of biochemistry and cellular organization challenge the RNA world paradigm | journal = Journal of Molecular Microbiology and Biotechnology | volume = 23 | issue = 1–2 | pages = 152–77 | year = 2013 | pmid = 23615203 | doi = 10.1159/000346551 | s2cid = 41725226 }}</ref><ref>{{cite journal | vauthors = Saladino R, Botta G, Pino S, Costanzo G, Di Mauro E | title = Genetics first or metabolism first? The formamide clue | journal = Chemical Society Reviews | volume = 41 | issue = 16 | pages = 5526–65 | date = August 2012 | pmid = 22684046 | doi = 10.1039/c2cs35066a | hdl = 11573/494138 }}</ref> their interactions with catalytic RNA would increase both the range and efficiency of function of catalytic RNA molecules.<ref name="Noller-2012" /> Thus, the driving force for the evolution of the ribosome from an ancient [[self-replicating machine]] into its current form as a translational machine may have been the selective pressure to incorporate proteins into the ribosome's self-replicating mechanisms, so as to increase its capacity for self-replication.<ref name="Root-Bernstein-2015" /><ref>{{cite journal | vauthors = Fox GE| title = Origin and Evolution of the Ribosome| journal = Cold Spring Harb Perspect Biol | volume = 2 | issue = 9 | date = September 2010 | pages = a003483| pmid = 20534711 | doi = 10.1101/cshperspect.a003483| pmc = 2926754| doi-access = free }}</ref><ref>{{cite book | vauthors = Fox GE | veditors = Hernández G, Jagus R| year = 2016| title = Evolution of the Protein Synthesis Machinery and Its Regulation| chapter= Origins and early evolution of the ribosome | url = https://doi.org/10.1007/978-3-319-39468-8 |pages=31–60|location = Switzerland  | publisher = Springer, Cham| doi = 10.1007/978-3-319-39468-8| isbn=978-3-319-39468-8 | s2cid = 27493054}}</ref>