Our hereditary material is replicated in full inside almost every cell in our body. Some 2m of DNA is expertly packed up inside microscopic cellular brain centres of the cell (nuclei). The very long molecule takes the form of a double helix; two strands twisted together to form a spiral backbone. And this helical coil is checked, altered and regulated by a group of DNA-binding proteins. Built to fit along one of two grooves that run the length of the helix, the zinc fingers on these proteins help them affix to DNA. Here, the zinc finger of a binding protein (in blue) is shown bound to a section of the double helix (pictured in green and red). The green dots are zinc ions, which play a key role in ensuring the protein takes on just the right shape to fit the helical DNA.
Written by Manisha Lalloo
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