Filamentous phage assembly.

Filamentous phages present a genetically well-defined system for studying the ordered membrane assembly of five different phage-encoded proteins around the circular single-stranded DNA phage genome. Assembly occurs at high efficiency in vivo, catalysed by two phage-encoded membrane proteins and at least one host protein, thioredoxin. This review presents a description of the virion and its cytoplasmic precursor and summarizes the results of genetic and biochemical experiments that are beginning to elucidate the role of the three morphogenetic proteins. The recent discovery of bacterial transport proteins with homology to a phage morphogenetic protein located in the outer membrane suggests the existence of a common mechanism for moving complex macromolecules across bacterial membranes.