Breakfast sandwich Breakfast sandwich In North America, a breakfast sandwich is any sandwich filled with foods associated with the breakfast meal. Breakfast sandwiches are served at fast food restaurants and delicatessens or bought as fast, ready to heat and eat sandwiches from a store. Breakfast sandwiches are commonly made at home. Breakfast sandwiches are typically made using breakfast meats (generally cured meats such as sausages, patty sausages, bacon, country ham, Spam and pork roll), breads, eggs and cheese. These sandwiches were typically regional specialties until fast food restaurants began serving breakfast. Because the common types of bread, such as biscuits, bagels, and
Stirrup protein domain Stirrup protein domain In molecular biology, the protein domain Stirrup is a domain, found only in found in the domain, archaea. The Stirrup protein domain is found in prokaryotic protein ribonucleotide reductases. It obtains its name due to its resemblance to an old fashioned Japanese stirrup. Stirrip has a molecular mass of 9 kDa and is folded into an alpha/beta structure. It allows for binding of the reductase to DNA via electrostatic interactions, since it has a predominance of positive charges distributed on its surface. This protein domain provides the precursors necessary for DNA synthesis. It catalyses the biosynthesis of