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Re: Dinosaur Protein

And, why does DNA not hold up so well?<<<

Some good answers have already made it to the list about the molecular reasons why DNA is suceptible to more rapid breakdown. As it's a biology-related mailing list, I wanted to point out that there are underlying evolutionary reasons for is. As many of you know DNA is not simply run from front to back through the protein synthesis machinery. Instead protein synthesis responds to a complex network of hormones and other intercellular communication, intracellular changes in chemical makeup, and environmental cues. DNA has to be able to be opened easily (e.g. unwrapped from histones and the needed portion transcribed), and this "flexibility" in conformation is synonymous with breaking down easily.

Collagen, on the other hand, is the tough, non-elastic protein in connective tissue, and has been selected to the opposite selective pressures the previous several billion years. In order to retain its shape and hold...whatever it's holding...in place, it needs to not respond to chemical alterations, and hence has evolved to be relatively innert.

So it really has to be this way, or else organisms as we understand them would not work. We could even hypothesize that if future paleontologists are ever working on a very different form of life (that evolved separately from Earth), that we will again be far more likely to recover connective tissue proteins, but much less likely to recover intact whatever molcule is used to store the instruction set for producing and maintainng an organism.

Scott Hartman Science Director Wyoming Dinosaur Center 110 Carter Ranch Rd. Thermopolis, WY 82443 (800) 455-3466 ext. 230 Cell: (307) 921-8333


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