The head-tail linker protein of bacteriophage T5: genetic and immunological studies

We investigated the properties of amber mutants of coliphage T5 defective in a late stage of phage assembly. The non-functional heads synthesized by mutants am25 or am158 were unable to combine with functional tails to produce viable phage particles. These mutants were shown to lack a single protein, designated the head-tail linker protein (HTLp), which was identified by polyacrylamide gel electrophoresis and Western blot analysis and had an Mr of 18,000. An extract containing the HTLp, when added to the HTLp-deficient heads, restored their ability to combine with functional tails.