Zinc Fingers
As you are browsing through the proteins in the PDB, you may notice something: most proteins are big. They contain hundreds of amino acids, even though most of the work is often done by a few amino acids on one side. Why are proteins so big? One reason that proteins are so large is that they must self-assemble inside cells. Proteins are built as floppy chains that fold all by themselves (or with a little help from chaperones) into stable, compact structures. These folded structures are stabilized by hydrogen bonds, charge-charge interactions and hydrophobic forces between the different amino acids, which all line up like pieces in a jigsaw puzzle when the protein folds. A single hydrogen bond or a few charge pairs would not be enough, but a chain of hundreds of amino acids has hundreds of interactions that together glue the protein into a stable structure.
Our cells, on the other hand, often use a zinc atom to take a short cut. By arranging two cysteines and two histidines close to each other in a chain, a protein can grab a zinc ion and fold tightly around it. In these proteins, termed zinc fingers, a short chain of 20-30 amino acids is enough to create a solid, stable structure. Zinc fingers are so useful that they are found in thousands of our proteins, and are common in all plants and animals. Surprisingly, however, bacteria do not appear to take advantage of these little structures. Many zinc fingers play essential roles in DNA recognition. Zinc fingers were originally discovered in the transcription factor TFIIIA from frog eggs, which contains nine zinc fingers in a row.
Our cells, on the other hand, often use a zinc atom to take a short cut. By arranging two cysteines and two histidines close to each other in a chain, a protein can grab a zinc ion and fold tightly around it. In these proteins, termed zinc fingers, a short chain of 20-30 amino acids is enough to create a solid, stable structure. Zinc fingers are so useful that they are found in thousands of our proteins, and are common in all plants and animals. Surprisingly, however, bacteria do not appear to take advantage of these little structures. Many zinc fingers play essential roles in DNA recognition. Zinc fingers were originally discovered in the transcription factor TFIIIA from frog eggs, which contains nine zinc fingers in a row.
Vote Count 2.1
Cerberus v666 - 1 (Ankamius)
hiplop - 5 (Tere, vezokpiraka, Sonic Boom, ZZZX, Flubbernugget)
Sonic Boom - 2 (hiplop, mastin2)
Tere - 1 (Shakira Confirmed)
Not Voting: Cerberus v666, ika, Jaqen Hghar, Kari, Lying Cat, Mac, Wickedestjr
9 to lynch. Deadline is in (expired on 2015-07-07 23:21:41)
