Non coding RNA

1. RNA,S
• Are known as Ribonucleic acids.
• These are chains of a Ribo nucleotides.
• Are the products of Central dogma of
molecular under transcription.
• The base of such nucleotides include Uracil
instead of that thymine in DNA

2. Nucleotides

3. Why RNA,s are essentially required?
• It is because,
 To proceed and maintenance of life / central dogma
 DNA needs proteins to replicate
 Proteins coded for by DNA
 RNA can be code and machinery
 Structural component
 Regulatory and catalytic functions

4. Non Coding RNA,S
• Non-coding RNA (ncRNA) is a RNA molecule
that functions without being translated into a
protein
• Most prominent examples: Transfer RNA
(tRNA), Ribosomal RNA (rRNA)

5. Nc DNA
DNA
RNA
proteinX

6. Non Coding RNA,S
• In higher eukaryotes, 98% are never translated
into proteins
• Of those 98%, about 50-70% are introns
• Others originate from non-protein genes,
including rRNA, tRNA and a vast number of other
non-coding RNAs (ncRNAs)
• Even introns have been shown to contain
ncRNAs, for example snoRNAs
• It is thought that there might be order of 10,000
different ncRNAs in mammalian genome

7. Types and Functions of RNAs
• CODING = messenger RNA (mRNA)
• translated into a protein
• NON-CODING (ncRNA) = not translated into a protein
• lot of different functions : splicing, translation, gene
• regulation ...
• rRNA Ribosomal RNA
• tRNA Transfer RNA
• snoRNA nucleosome, rRNA-editing
• miRNA Control of gene expression on the translation
• level

9. Ribosomal RNA
• First discovered in the
1930s as part of the
microsome by Albert
Claude
• Characterized as a
ribosomal component
in the 1950s by George
Palade

10. RRNA
Known as ribosomal RNA
The characteristics include,
• Stable RNA
• Constitute 80% of RNA in cell.
• Synthesize in Nucleolus.
• Found in Ribosomes

11. RRNA synthesize in
• Form in nucleolus from specified rDNA
• Bases are slightly modified
• Usually 4 types of rRNA found in eukaryotes
• rRNA plus ribosomal proteins form ribosomes
• Mitochondria and chloroplasts have their own
rRNA genes

12. functions
• Ribosomal RNA (rRNA) associates with a set of
proteins to form ribosomes.
• Involves ,catalyze & assembly of amino acids
into protein chains.
• They also bind tRNAs and various accessory
molecules necessary for protein synthesis.
• Being part of ribosomes component of
evolutionary characteristics.

13. tRNA
• Transfer RNA
• tRNAs function as carriers of amino acids and
participate in protein synthesis.
• Transfer RNA (tRNA) serves as the nucleic acid
decoding device that reads the triplet genetic
code of messenger RNA
• (Holley received the Nobel Prize on describing
structure of tRNA

14. tRNA
The genetic code is read during translation via
adapter molecules, tRNAs, that have 3-base
anticodons complementary to codons in mRNA.
"Wobble" during reading of the mRNA allows some
tRNAs to read multiple codons that differ only in the
3rd base.
There are 61 codons specifying 20 amino acids.
Minimally 31 tRNAs are required for translation, not
counting the tRNA that codes for chain initiation.
Mammalian cells produce more than 150 tRNAs.

16. functions
• Associate with codon insertion
• Generally it has tertiary structure
• Consist of loops and and anticodon loops with
a wobble positions which favours
• Translation
• Recognition of codons
• Transport of amino acids

17. Structure of tRNA

18. The two main classes of ncRNAs
1. Housekeeping ncRNAs, which are constitutively
expressed and required for normal function and
viability of cell
eg TRNAs. RRNAs
2. Regulatory ncRNAs are expressed only in certain
stages of organism development or as a response to
external stimuli.
• Regulatory ncRNAs can affect the expression of other
genes at the level of transcription or translation

19. Other nc RNAs
• MicroRNA
• new discovery,short noncodimg DNA
• Gene regulation on the translation level
• Short sequences (~22bp)
• Hairpin structure (processed)
• How is miRNA processed (Ghosh et al. 2007)
• Binding to mRNA
• Binding sites on 5' and 3' UTRs
• cleavage of mRNA

20. Functions
• Statistically biased (codon triplets)
Stop codons
• High CG content (hyperthermophiles)
• Promoter/Terminator identification (E. Coli)
• Primers
• Signal recognition Particles
• Gene silencing
• Regulation of translation
• Ligating ribozymes favours neurological functions

21. Housekeeping ncRNAs
• tRNA and rRNA - translation
• snRNA – Pre-mRNA splicing
• snoRNA – rRNA modification
• gRNA – guide RNA in RNA editing
• Telomerase RNA – primer for telomeric
DNA synhesis
• A few other...

22. Ribozymes
• RNA molecules with catalytical properties (Ribonucleic acid
enzymes)
• In nature ribozymes involves in
• self-splicing intrones
• RNA encoded parasites
• The catalytical efficiency of ribozymes is lower analogous protein
enzymes
• Several synthetic ribozymes are cabaple of performing other
reactions than RNA cleavage and ligation
• RNAse P cleaves the 5’ end of pre-tRNAs
• It is composed of 12 kDa P protein and about 400 nt long RNA

23. Cp RNA
• 3 rRNAs (23S, 16S, 5S)
• 30 tRNAs for recognition of
• all codons
• roughly 40 proteins of known function
• Proteins include TIC and Tocs
• subunits of ribosomes

24. functions

25. Mt RNA
• Mitochondrial DNA codes for 37 genes
• coding for
• 13 proteins,
• 22 mt transfer RNAs
• 2 ribosomal RNAs (rRNAs).
Rna promote cellular matabolism n catabolism

26. function

28. Other functions involve
• Structural components
• Telomers in chromatin
• Ribosomes
• Regulations
Gene silencing by RNA interference
Cellular Maintenance
Cause cancer
Alzhemier disease etc

29. THANKS!