The phage λ major tail protein structure reveals a common evolution for long-tailed phages and the type VI bacterial secretion system

• DOI: 10.1073/pnas.0900044106
• Publication Date: 2009-02-28T02:11:49Z
• Authors: Lisa G. Pell; Voula Kanelis; Logan W. Donaldson; P. Lynne Howell; Alan R. Davidson
• Keywords: Structural protein

Most bacteriophages possess long tails, which serve as the conduit for genome delivery. We report solution structure of N-terminal domain gpV, protein comprising major portion noncontractile phage λ tail tube. This is very similar to a previously solved tube from contractile-tailed phage, providing first direct evidence an evolutionary connection between these 2 distinct types tails. A remarkable structural similarity also seen Hcp1, component bacterial type VI secretion system. The hexameric Hcp1 and its ability form tubes are strikingly reminiscent gpV when it polymerized into These data coupled with other similarities proteins support relationship systems. Using model, we propose polymerization mechanism involving several disorder-to-order transitions.