Protein targeting by the twin-arginine translocation pathway

The twin-arginine translocation pathway operates in the thylakoid membrane of chloroplasts and in the plasma membrane of most free-living bacteria. It s main function is to transport fully folded proteins across the membrane. Three important tat genes have been identified and the sequences of the enc oded proteins, together with the unusual properties of the pathway, indicat e that the Tat system is completely different from other protein translocas es.