About author :
Jony Mallik*, Abdullah Al Faruq, Sourav Das
Department of Pharmacy,
Southern University Bangladesh, Chittagong, Bangladesh
*e-mail: [email protected]
Deoxyribonucleic acid (DNA), is a biological molecule present in the chromosome of the nucleus of cell. DNA is made of sequential association of two polynucleotide chain consisting of deoxyribose sugar, inorganic phosphate (ip) & nucleobases (adenine, guanine, thiamine, cytosine). The helical structure of DNA is very natural which was discovered by James Watson and Francis Crick in 1953. The genetic information is actually immersed within the base sequences of DNA hence it’s called “Reserve Bank of Genetic Information”. DNA is acts as a precursor for the synthesis of Protein, which is a part of nutrition and most of the hormones. Pharmaceutical active principles need specific protein in plasma for binding to form equilibrium condition with unbound one. Naturally DNA transfer its information to Ribonucleic acid (RNA) and then to protein. It’s a routine pathway of our body where RNA is the intermediate. This pathway is called “Central Dogma”.
Key words: Ribonucleic acid (RNA), Protein, Deoxyribonucleic acid (DNA), Central Dogma.
BASICS OF CENTRAL DOGMA :
DNA is the carrier of genetic information in organisms. For body individual needs the information transferred into mRNA (messenger RNA) where the information read and transfer to biologically important molecules called protein. It is the Central Dogma of molecular biology.
DNA –> RNA –> Protein
Two very vital process involved in performing central dogma activities. One is Transcription (DNA to RNA) and another one is Translation (RNA to Protein).
Transcription is the preliminary process of central dogma which acts on DNA to RNA formation. A number of biological activities involved there
1. Binding of RNA polymerase (with sigma factor) to the promoter region of DNA. (Initiation).
2. Sigma factor participates in detecting the promoter region.
3. Soon after binding of RNA polymerase, it moves along the DNA template.
4. Thread like mRNA is escape out from DNA by matching the sequences of nucleobases of DNA via codon and anticodon .
5. The primer being separate again after completion of overall process (Termination)
RNA differs from DNA in that RNA contains a ribose, not deoxyribose, sugar in its backbone. RNA lacks the base Thiamin, it is replaced, instead, with the base Uracil, which is complementary to Adenine. The RNA formed acts as a messenger, which passes from the nucleus into the cytoplasm of the cell. In fact, this type of RNA is often called messenger RNA, mRNA. Since the information in a nucleic acid (DNA) is converted into information in the form of another nucleic acid (RNA), this process is called transcription .
Translation is the finale process of central dogma which acts on RNA to Protein formation. A number of biological activities involved there
1. Binding of tRNA (transfer RNA) to the mRNA . tRNA has a specific amino acid binding site. The lower portion of tRNA has codon and anticodon matching site.
2. Binding of particular amino acids to tRNA by forming peptide linkage and this step is repeated to elongate the amino acid chain.
3. Activation of termination factor (TF) to stop the process and cut the chain by restriction enzyme.
The monomer in a protein is called an amino acid, a completely different kind of molecule than a nucleotide. There are twenty different naturally occurring amino acids that differ in one of the 4 groups connected to the central carbon. In an amino acid, the central (alpha) carbon has an amine group (RNH2), a carboxylic acid group (RCO2H), and H, and an R group attached to it. Since the information in a nucleic acid (RNA) is converted into information in the form of a different molecule, a protein, this process is called translation
Central dogma is a miraculous molecular biological pathway because numerous proteins are systhesized by this pathway and it is the only way of synthesizing protein. If any alteration occurs in DNA base sequences (mutation), the overall process become hampered and protein will synthesize with fault in sequence which may cause genetical diseases to human being. Now a days most of the people worldwide are suffering from genetical disorder, which is just because of the fault in Central Dogma. So we can say, it’s a miraculous and sensitive pathway of molecular biology.