Dynamic localization of tat protein transport machinery components in Streptomyces coelicolor

The Tat pathway transports folded proteins across the bacterial cytoplasmicmembrane and is amajor route of protein export in the Streptomyces genus of bacteria. In this study, we have examined the localization of Tat components in themodel organism Streptomyces coelicolor by constructing enhanced green uorescent protein (eGFP) andmCherry fusions with the TatA, TatB, and TatC proteins. All three components colocalized dynamically in the vegetative hyphae, with foci of each tagged protein being prominent at the tips of emerging germtubes and of the vegetative hyphae, suggesting that thismay be a primary site of Tat se-cretion. Time-lapse imaging revealed that localization of the Tat components was highly dynamic during tip growth and again demonstrated a strong preference for apical sites in growing hyphae. During aerial hypha formation, TatA-eGFP and TatB-eGFP fusions relocalized to prespore compartments, indicating repositioning of Tat components during the Streptomyces life cycle.