Trichilemmal cyst Trichilemmal cyst A trichilemmal cyst, also known as a wen, pilar cyst or isthmus-catagen cyst, is a common cyst that forms from a hair follicle. They are most often found on the scalp. The cysts are smooth, mobile and filled with keratin, a protein component found in hair, nails, skin, and horns. They are, however, clinically and histologically distinct from trichilemmal horns, which are much more rare and not limited to the scalp. Trichilemmal cysts may run in families and they may or may not be inflamed and tender, often depending on whether they have ruptured. Rarely, these cysts may
YqaJ protein domain YqaJ protein domain In molecular biology, the YqaJ refers to the YqaJ/K domain from the "skin" prophage of the bacterium, "Bacillus subtilis". This protein domain, often found in bacterial species, is actually of viral origin. The protein forms an oligomer and functions as an alkaline exonuclease, or in simpler terms, an enzyme that digests double-stranded DNA. It is a reaction which is dependent on Magnesium. It has a preference for 5'-phosphorylated DNA ends. It thus forms part of the two-component SynExo viral recombinase functional unit. The function of this protein domain is to digest DNA. Most viruses, inject their host