A novel protein transport system involved in the biogenesis of bacterial electron transfer chains

The Tat system is a recently discovered bacterial protein transport pathway that functions primarily in the biosynthesis of proteins containing redox active cofactors. Analogous transport systems are found in plant organelles . Remarkably and uniquely the Tat system functions to transported a diverse range of folded proteins across a biological membrane, a feat that must be achieved without rendering the membrane freely permeable to protons and ot her ions. Here we review the operation of the bacterial Tat system and prop ose a model for the structural organisation of the Tat preprotein transloca se. (C) 2000 Elsevier Science B.V. All rights reserved.