The ever expanding world of RNA
RNA or ribonucleic acids differ from DNA or deoxyribonucleic acids in having the sugar ribose in place of deoxyribose as well as having one less oxygen atom at the ribose. Secondly, in RNA the base thymine (T) is replaced with uracil (U). So the genetic alphabet has five letters: A, C, G, T and U.
The RNA World
When I was a kid I remember that when working in the fields of my father’s farm together with my late grandfather we where tossing a bunch of questions around during our regular spreading of manure onto the fields to fertilize them.
One of these questions was “What came first, the chicken or the egg?” This was before I knew of the science of molecular biology and many years later finally earned a Ph. D. in cell biology.
Now the question has evolved to “What came first proteins, DNA or RNA?”
The RNA world hypothesis, first supported by Carl Woese in 1967, speculates that the origin of life got started by simple self replicating RNA molecules that through natural selection may have evolved into life as we know it today. Furthermore, the “RNA world” refers to a hypothetical stage in the origin of life on Earth in which RNA carried out the storage of information and acted as an enzyme as well. This hypothesis assumes that RNA molecules assembled themselves randomly in the primordial soup and carried out simple metabolic activities. The discoveries of self splicing RNA molecules, ribozymes, ribosomes and RNA based molecular switches are now considered as a support for this hypothesis.
*
Today, using improved synthetic and biochemical methods, DNA polymers, long and small double stranded DNA and RNA molecules, RNA polymers, small and large peptides and small proteins can now be routinely synthesized.
*
New generations of artificial nucleic acid such as bridged nucleic acids (BNAs) are promising tools for the study of the expanding RNA world.
*
We at Biosynthesis Inc. can help you with all your synthesis needs.
*
Please contact us at: http://www.biosyn.com
or call us at
1-800-227-0627
*
The following shows a collections of abbreviations for different types of RNA families
RNAs that are important for protein synthesis
Abbreviation | Type | Function | Found in |
mRNA | Messenger RNA | Codes for proteins | All organisms |
rRNA | Ribosomal RNA | Translation | All organisms |
7SL RNA or SRP RNA | Signal recognition particle RNA | Membrane integration | All organisms |
tRNA | Transfer RNA | Translation | All organisms |
tmRNA | Transfer-messenger RNA | Transfer and messenger RNARescues stalled ribosomesMediates degradation of the aberrant mRNA.Adds a degradation tag to the aberrant protein for directed proteolysis | All organisms |
RNAs involved in post-transcriptional modification or DNA replication
Abbreviation | Type | Function | Found in |
snRNA | Small nuclear RNA | Splicing and other fucntions | Eukaryotes and archaea |
snoRNA | Small nucleolar RNA | Nucleotide modification of RNAs | Eukaryotes and archaea |
SmY | SmY RNA | mRNA trans-splicing | Nematodes |
scaRNA | Small Cajal body-specific RNA | Type of snoRNA; Nucleotide modification of RNAs | |
gRNA | Guide RNA | gRNA mRNA nucleotide modification | Kinetoplastid mitochondria |
RNase P | Ribonuclease P | tRNA maturation. Ribozyme that cleaves RNA. | All organisms |
RNase MRP | Ribonuclease MRP | rRNA maturation and DNA replication | Eukaryotes |
Y | Y RNA | RNA processing and DNA replication | Animals |
telRNA | Telomerase RNA | Telomere synthesis | Most eukaryotes |
slRNA | Spliced leader RNA | SL1 RNA located in the spacer region between 5S-rRNA genes where it is involved in trans-splicing | Eukaryotes |
Regulatory RNAs
Abbreviation | Type | Function | Found in |
aRNA | Antisense RNA | Transcriptional attenuationmRNA degradationmRNA stabilizationTranslation block | All organisms |
Chi sgRNA | Chimeric single guide RNA | Functional portion of crRNA and tracrRNA to form a targeted RNA-guided endonuclease (RGEN) | |
cnaRNA | Cis-natural antisense transcript RNA | Gene regulation. Natural antisense transcripts (NATs) | Multipe eukaryotes |
crRNA | CRISPR RNA | Resistance to parasites, probably by targeting their DNA | Bacteria and archaea |
esiRNA | Endoribonuclease prepared siRNAs | Endoribonuclease prepared siRNAs (esiRNAs) are complex pools of siRNAs, which are produced from a long dsRNA by digestion with an enzyme from the RNaseIII family that mimic ex vivo the digestion by the protein Dicer. | |
gRNA | Guide RNA | Guides the insertion or deletion of uridine residues into mitochondrial mRNAs in a process known as RNA editing. | kinetoplastid protists |
lncRNA | Long noncoding RNA | Various functions | Eukaryotes |
miRNA | MicroRNA | Gene regulation | Most eukaryotes |
piRNA | Piwi-interacting RNA | Transposon defense and maybe other functions | Most animals |
Pro-siRNA | His-tagged p19 long hairpin RNA | Engineered His-p19 long (.100 nt) hairpin RNA encoding sense and antisense strands specific for target genes allows purification of ~21 nt RNAs called pro-siRNAs | |
RNAi | Interference RNA | Gene regulation. Repression of gene expression | Most eukaryotes |
sgRNA | Single guide RNA | Mitochondrial mRNA editing | Bacteria Trypanosoma brucei |
shRNA | Short –hairpin RNA | Gene silencing | Mammals |
siRNA | Small-interfering RNA; RNAi | Gene regulation. Repression of gene expression | Most eukaryotes |
tasiRNA | Trans-acting RNA | Gene regulation | Land plants |
tracrRNA | Trans-activating crRNAs | Guide the enzyme Cas9 endonuclease to recognize and cleave a site in non self DNAAdaptive i\mmune system. | Bacteria and archaea |
rasiRNA | Repeat associated siRNA | Type of piRNA; transposon defense | Drosophila |
7SK | 7SK RNA | 7SK negatively regulating CDK9/cyclin T complex |
Parasitic RNAs
Type | Function | Found in |
Retrotransposones | Self-propagating | Eukaryotes and some bacteria |
Viral genome | Information carrier | Double-stranded RNA viruses, positive-sense RNA viruses, negative-sense RNA viruses, many satellite viruses and reverse transcribing viruses |
Viroid | Self-propagating | Infected plants |
Satellite RNA | Self-propagating | Infected cells |
Other RNAs
Abbreviation | Type | Function | Found in |
5’-AppRNA | 5’-adenylated RNA | Plays a central role in nucleic acid ligation | Bacteriophage T4 |
cfRNA | Cell-free RNA | cfRNA are found to circulated in human blood in cancer patients | Humans |
dsRNA | Double stranded RNA | dsRNA induce RNAi | |
L ds RNA | Long double-stranded RNA | ||
pRNA | Bacteriophage pRNA | Packaging of the viral genome into a pre-fromed viral procapsid | Bacteriophages |
S dsRNA | Short double-stranded RNA | ||
ssRNA | Single stranded RNA | ||
vRNA or vtRNA | Vault RNAs | Expulsion of xenobiotics; drug resistence | Humans
Rodents Bullfrog |
.
Categories: BNA RNA, DNA, DNA Analysis, DNA Editing, DNA finger printing, Epigenetics, Gene Expression, lncRNA, Long noncoding RNA, miRNA, non-coding RNAs, Oligonucleotide Synthesis, RNA Editing, RNA silencing, RNA World, RNA World Hypothesis, RNAi, Virus
Leave a Reply