Type I protein secretion is a system in some Gram-negative bacteria to export proteins (often proteases) across both inner and outer membranes to the extracellular medium. This is one of three proteins of the type I secretion apparatus. Targeted proteins are not cleaved at the N-terminus, but rather carry signals located toward the extreme C-terminus to direct type I secretion. This model is related to models TIGR01842 and TIGR01846, and to bacteriocin ABC transporters that cleave their substrates during export. [Protein fate, Protein and peptide secretion and trafficking, Cellular processes, Pathogenesis]
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