"

From 2010.igem.org

Theory

Gene:

It is the unit of inheritance in living beings. In common biological terms, it is a stretch of DNA that codes for a protein or a particular RNA which has some function in the cell. The functional structure of a gene has two basic components a regulatory system and a coding region. The common part in the regulatory systems of almost all genes is the promoter. The promoter usually marks the beginning of the gene and the terminator sequence marks its end. There is a 6-7 base pair region upstream the start codon (AUG) in prokaryotes called the ribosomal binding site (also known as Shine – Dalgarno Sequence) which is required for the conversion of m-RNA to protein.

Promoter:

It is a region on DNA that facilitates the transcription (production of RNA from DNA) of a gene. They are usually located upstream of the gene they control, on the 5’end of the sense strand. The promoters contain specific DNA sequence for the initial binding of the RNA polymerase enzyme. The strength of the promoter depends on the interaction of the DNA binding domain of the polymerase enzyme and the sequence of the promoter. This strength is also sometime modulated by other distant DNA fragments called enhancers.

RBS:

This sequence is complementary to the 3' end of the r-RNA. The ribosome searches for this site and binds to it through base-pairing of nucleotides. Then, the ribosome begins the translation process and recruits initiation factors to make the protein.

Gene Expression:

There are two phenomenon (Transcription and Translation) which taken together comprise gene expression i.e. production of a protein from gene. The coding region of a gene has different triplet codons for different amino acids. This code is transcribed into m-RNA by the complicated phenomenon called Transcription which is carried out by the RNA polymerase enzyme complex. The genetic information of the messenger RNA is then converted to a polypeptide sequence at the ribosome complex and the protein is formed. The protein is then used by the cell for different purposes or it is exported out. The export is facilitated by specific polypeptide sequences called export tags. One of the basic parts we have submitted is one such export tag called sp310mut2 which can be used export GM proteins out in the extra-cellular medium.