L20 ribosomal protein leader is a

ribosomal protein leader A ribosomal protein leader is a mechanism used in cells to control the cellular concentration of a protein that forms a part of the ribosome, and to make sure that the concentration is neither too high nor too low. Ribosomal protein leaders are RNA ...

involved in the

ribosome biogenesis Ribosome biogenesis is the process of making ribosomes. In prokaryotes, this process takes place in the cytoplasm with the transcription of many ribosome gene operons. In eukaryotes, it takes place both in the cytoplasm and in the nucleolus. I ...

. It is used as an autoregulatory mechanism to control the concentration of

ribosomal protein A ribosomal protein (r-protein or rProtein) is any of the proteins that, in conjunction with rRNA, make up the ribosomal subunits involved in the cellular process of translation. ''E. coli'', other bacteria and Archaea have a 30S small subunit an ...

s L20. The structure is typically located in the 5′ untranslated regions of

mRNAs In molecular biology, messenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of synthesizing a protein. mRNA is created during the p ...

encoding initiation factor 3 followed by

ribosomal proteins A ribosomal protein (r-protein or rProtein) is any of the proteins that, in conjunction with rRNA, make up the ribosomal subunits involved in the cellular process of translation. ''E. coli'', other bacteria and Archaea have a 30S small subunit an ...

L35 and L20 (infC-rpmI-rplT), but the regulated mRNAs always contain an L20 gene. A

Rho Rho (uppercase Ρ, lowercase ρ or ; el, ρο or el, ρω, label=none) is the 17th letter of the Greek alphabet. In the system of Greek numerals it has a value of 100. It is derived from Phoenician letter res . Its uppercase form uses the sa ...

-independent

transcription Transcription refers to the process of converting sounds (voice, music etc.) into letters or musical notes, or producing a copy of something in another medium, including: Genetics * Transcription (biology), the copying of DNA into RNA, the fir ...

terminator structure that is probably involved in regulation is included at the 3′ end in many examples of L20 ribosomal protein leaders. Three structurally distinct forms of L20 leaders have been experimentally established. One such leader motif occurs in

Bacillota The Bacillota (synonym Firmicutes) are a phylum of bacteria, most of which have gram-positive cell wall structure. The renaming of phyla such as Firmicutes in 2021 remains controversial among microbiologists, many of whom continue to use the earl ...

and the other two are found in

Gammaproteobacteria Gammaproteobacteria is a class of bacteria in the phylum Pseudomonadota (synonym Proteobacteria). It contains about 250 genera, which makes it the most genera-rich taxon of the Prokaryotes. Several medically, ecologically, and scientifically imp ...

. Of the latter two, one is found in a wide variety of Gammaproteobacteria, while the other is only reported in ''

Escherichia coli ''Escherichia coli'' (),Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. also known as ''E. coli'' (), is a Gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus ''Escher ...

''. All three types of leader exhibit apparent similarities to the region of

Ribosomal RNA Ribosomal ribonucleic acid (rRNA) is a type of non-coding RNA which is the primary component of ribosomes, essential to all cells. rRNA is a ribozyme which carries out protein synthesis in ribosomes. Ribosomal RNA is transcribed from ribosomal ...

to which the L20

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

normally binds. However, in terms of

RNA secondary structure Nucleic acid secondary structure is the basepairing interactions within a single nucleic acid polymer or between two polymers. It can be represented as a list of bases which are paired in a nucleic acid molecule. The secondary structures of biolo ...

, the context of the similar region is distinct in each leader type. A fourth example of an L20 ribosomal protein leader was predicted in

Deltaproteobacteria The Myxococcota are a phylum of bacteria known as the fruiting gliding bacteria. All species of this group are Gram-negative. They are predominantly aerobic genera that release myxospores in unfavorable environments. Phylogeny The currently acce ...

using

bioinformatic Bioinformatics () is an interdisciplinary field that develops methods and software tools for understanding biological data, in particular when the data sets are large and complex. As an interdisciplinary field of science, bioinformatics combine ...

approaches. Like the three experimentally validated kinds of leader, the Deltaproteobacterial version resembles the relevant portion of ribosomal RNA, but presents this similarity in yet another structural context.

References

External links

* Ribosomal protein leader {{molecular-cell-biology-stub

See also

References

External links