I am sorry, there is no real post either today. Just something to look at. This is the demo protein from PyMOL. You can see the α-helices and the β-sheets. In between you have loops, areas with no ordered secondary structure. These loops make the protein more hydrophilic because O and N can form hydrogen bonds to water when they are not bonded to each other. The active sites are mostly contained in loops because they are easier accessible. Loops are also the places where most mutations occur. Mutations in α-helices or β-sheets may mess up the structure but mutations in loops can stay because there is no structure to mess up .
As Mike said, the situation is not quite as easy because there is much more than helices and sheets making up a protein's structure.
Macrocycles, flexibility and biological activity: A tortuous pairing - Here's an interesting paper from the Jacobson, Wells and Walsh labs at UCSF and Stanford that seeks to demonstrate how restricting the flexibility of macr...
3 days ago