L13 ribosomal protein leaders play a role in ribosome biogenesis as part of an autoregulatory mechanism to control the concentration of ribosomal proteins L13. Three structural classes of L13 ribosomal protein leaders were detected by different bioinformatics approaches: in B. subtilis and other low-GC Gram-positive bacteria., in E. coli and in Bacteroidia. Although these RNAs are expected to perform the same biological function, they do not appear to be structurally related to one another. The E. coli example has been experimentally confirmed, though the experiments are not comprehensive. The other two leader structures are thus far not based on experimental support.
L19 Ribosomal protein leaders are part of the ribosome biogenesis. They are used as an autoregulatory mechanism to control the concentration of ribosomal proteins L19, and are located in the 5′ untranslated regions of mRNAs encoding ribosomal protein L19 (rplS). L19 ribosomal protein leaders have been bioinformatically predicted in B. subtilis and other low-GC Gram-positive bacteria in the phylum Bacillota. More examples that share a similar structure were predicted in Flavobacteria, also using bioinformatic approaches.
L20 ribosomal protein leader is a ribosomal protein leader involved in the ribosome biogenesis. It is used as an autoregulatory mechanism to control the concentration of ribosomal proteins L20. The structure is typically located in the 5′ untranslated regions of mRNAs encoding initiation factor 3 followed by ribosomal proteins L35 and L20 (infC-rpmI-rplT), but the regulated mRNAs always contain an L20 gene. A Rho-independent transcription 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 and the other two are found in Gammaproteobacteria. Of the latter two, one is found in a wide variety of Gammaproteobacteria, while the other is only reported in Escherichia coli. All three types of leader exhibit apparent similarities to the region of Ribosomal RNA to which the L20 protein normally binds. However, in terms of RNA secondary structure, the context of the similar region is distinct in each leader type.
S15 Ribosomal protein leaders perform an important regulatory function in ribosome biogenesis. They were used as an autoregulatory mechanism to control the concentration of ribosomal proteins S15. The structure is located in the 5′ untranslated regions of mRNAs encoding ribosomal proteins S15 (rpsO). Multiple distinct structural types of S15 ribosomal protein leaders are known in different organisms.
In molecular biology, SNORD15 is a non-coding RNA (ncRNA) molecule which functions in the modification of other small nuclear RNAs (snRNAs). This type of modifying RNA is usually located in the nucleolus of the eukaryotic cell which is a major site of snRNA biogenesis. It is known as a small nucleolar RNA (snoRNA) and also often referred to as a guide RNA.
60S ribosomal protein L5 is a protein that in humans is encoded by the RPL5 gene.
60S ribosomal protein L7a is a protein that in humans is encoded by the RPL7A gene.
60S ribosomal protein L6 is a protein that in humans is encoded by the RPL6 gene.
60S ribosomal protein L7 is a protein that in humans is encoded by the RPL7 gene.
60S ribosomal protein L4 is a protein that in humans is encoded by the RPL4 gene.
40S ribosomal protein S26 is a protein that in humans is encoded by the RPS26 gene.
60S ribosomal protein L22 is a protein that in humans is encoded by the RPL22 gene on Chromosome 1.
40S ribosomal protein S20 is a protein that in humans is encoded by the RPS20 gene.
39S ribosomal protein L12, mitochondrial is a protein that in humans is encoded by the MRPL12 gene.
39S ribosomal protein L19, mitochondrial is a protein that in humans is encoded by the MRPL19 gene.
60S ribosomal protein L26 is a protein that in humans is encoded by the RPL26 gene.
39S ribosomal protein L40, mitochondrial is a protein that in humans is encoded by the MRPL40 gene.
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 sequences that are a part of the 5' UTR of mRNAs encoding a ribosomal protein. When cellular concentrations of the ribosomal protein are high, excess protein will bind to the mRNA leader. This binding event can lower gene expression via a number of mechanisms; for example, in the protein-bound state, the RNA could form an intrinsic transcription termination stem-loop. When cellular concentrations of the ribosomal protein are not high, they are occupied in the ribosome, and are not available in significant quantities to bind the mRNA leader. This leads to increased expression of the gene, which leads to the synthesis of more copies of the ribosomal protein. Many examples of ribosomal protein leaders are known in bacteria, including ribosomal protein L20 leader and ribosomal S15 leader. Ribosomal leaders typically bind ribosomal proteins that normally bind ribosomal RNA. In many cases, the binding site within the leader structurally resembles the region of the ribosomal RNA to which the protein binds, in an example of molecular mimicry.
The L2 ribosomal protein leader is a ribosomal protein leader involved in ribosome biogenesis. It is used as an autoregulatory mechanism to control the concentration of the ribosomal protein L2. Known Examples were predicted in Alphaproteobacteria with bioinformatic approaches. The structure is located in the 5′ untranslated regions of mRNAs encoding ribosomal proteins L2 (rplB), S30 (rpsS), L22 (rplV) and S3 (rpsC). It was proposed that the ligand is uncertain, because none of the downstream (regulated) genes are known as a previously established ribosomal protein leader ligand.
S10 ribosomal protein leader is a ribosomal protein leader involved in the ribosome biogenesis. It is used as an autoregulatory mechanism to control the concentration of the ribosomal protein S10. Known Examples were predicted in Clostridia or other lineages of Bacillota with bioinformatic approaches. The structure is located in the 5′ untranslated regions of mRNAs encoding ribosomal proteins S10 (rpsJ), L3 (rplc) and L4 (rplD). There is an uncertainty about the ligand, because of a lack of experimental investigation.
