How does the energy for contraction get built into the tails of myophages?

Phage tails are complex macromolecular structures that play a critical role in host recognition, and DNA ejection. Based on the type of tail attached to the head, dsDNA phages can be divided into three types: siphophages (long, flexible, non-contractile tail), myophages (rigid but contractile tail), and podophages (short stubby tail). We at the Center for Phage Technology are particularly interested in studying the assembly of the contractile tail of myophages. (See figure.) When, after attachment to the cell surface, the myophage tail sheath undergoes contraction, the tail tube is driven through the outer membrane of Gram-negative bacteria, ultimately interacting with the cytoplasmic membrane and allowing the phage DNA to pass into the cell. Somehow, mechanical energy for this process is built into the phage tail during assembly. Recently we and our collaborators discovered that some myophages are unable to make functional tails in certain E. coli mutants. An intriguing idea is that these mutants fail in supplying the energy to “cock” the contractile tail


We are looking for an enthusiastic undergrad researcher to work on this project. It involves cloning the tail gene clusters of the myophage into a plasmid expression system and optimizing conditions for in vitro assembly of functional tails.

Contact Karthik Chamakura, CPT graduate student to get more information or apply.