Life's dynamic proteins (Introduction)

by David Turell , Thursday, January 07, 2016, 14:40 (3242 days ago) @ David Turell

Another active molecule takes two forms to facilitate or repress DNA action:-http://phys.org/news/2016-01-ancient-protein-flexibility-functions.html-"A protein called the glucocorticoid receptor or GR, which responds to the stress hormone cortisol, can take on two different forms to bind DNA: one for activating gene activity, and one for repressing it.-***-"GR is part of a family of steroid receptor proteins that control cells' responses to hormones such as estrogen, testosterone and aldosterone. Our genomes contain separate genes encoding each one. Scientists think that this family evolved by gene duplication, branch by branch, from a single ancestor present in primitive vertebrates.-"When GR turns genes on, two protein molecules grasp each other while binding to DNA. When it turns genes off, the two protein molecules bind on opposite sides of the DNA helix, adopting a slightly different shape to do so.-"The repressive mode is thought to be responsible for the inhibitory effects of cortisol and GR on the immune system. The other steroid receptor family members only bind DNA in the activating mode."-Same Comment: Chance found these molecules to use in life so specifically? I doubt it.