Dna Protein Interaction Report

INTRODUCTION:

DNA as well as Proteins are very essential macromolecules for any living cell. They are involved in various bio-molecular function, hence very essential for any living being. DNA protein interaction is one of the key biological function in a living cell. This type of interaction is happened during replication, transcription, translation, recombination, DNA repair, etc. DNA is a negatively charged macro molecule. Protein interact with the DNA with its positively charged residues. Protein molecule interact with DNA by means of hydrogen bonding mainly. The hydrogen bonding play an essential role for many bio-molecular interaction. We can found this kind of interaction during protein-protein interaction, DNA protein interaction,

It can also evolve independently. DNA binding domain is one of this kind which possess at least one motif which can recognize a single stranded or a double stranded DNA. There are several DNA binding motif has been found to be present. viz- Helix-turn-helix, Leucine zipper, Zinc finger, etc. In two ways DNA binding protein can interact with the target DNA. It can bind to the target DNA in a sequence specific manner, where the DNA binding domain can recognize and bind to a specific sequence of the DNA, which is called recognition sequence. This type of interaction is call 'sequence specific DNA-protein interaction'. Sometimes the DNA binding domain can randomly bind to a double stranded as well as a single stranded DNA. It is called 'sequence non-specific DNA-protein interaction'. Both of the sequence specific DNA-protein interaction, and sequence non-specific interaction are essential for life. A sequence specific DNA-protein interaction is found to be occurred during transcription, where a transcription factor interact in a specific sequence of a DNA. And a sequence non-specific DNA-protein interaction is found to be occurred when DNA interact with histone protein, in a sequence independent manner,

The wider grooves(22 Å) are called major grooves and the comparatively less wider grooves(12 Å) are called minor groove. Due to the much wideness of a major groove, it can provide a better exposure of the nucleotide bases than the minor groove. In case of sequence specific DNA-protein interaction, the DNA binding proteins interact in the major groove of the DNA. It use the exposure of nucleotide bases in the major groove, which helps the DNA binding protein to identify the specific sequence. But the minor groove cannot provide a sufficient exposure for a DNA binding protein, where it can distinguish a specific sequence. A diagrammatic explanation is