Stx1aencoded
Stx1aencoded refers to the genetic element that encodes the A subunit of Shiga toxin type 1 (Stx1), typically the stx1A gene found in certain Escherichia coli and Shigella strains. The toxin is an AB5 toxin, consisting of one A subunit (Stx1a) and a pentamer of B subunits (Stx1B). The stx1A and stx1B genes are commonly carried together on a lambdoid phage integrated into the bacterial chromosome, and their presence can vary between strains due to horizontal gene transfer.
Genetic and expression context: The stx1A and stx1B genes are part of a phage-encoded toxin cassette. Expression
Mechanism of action: The Stx1a A subunit is an N-glycosidase that cleaves a specific adenine residue from
Clinical relevance: Stx1a-encoded toxins contribute to diseases associated with Shiga toxin–producing bacteria, including hemorrhagic colitis and
See also: Shiga toxin, Stx1, stx1A, stx1B, phage-encoded toxins.