Studies on the morphopoiesis of the head of phage T-even: I. Morphological, immunological, and genetic characterization of polyheads

摘要: Conditional lethal mutations in gene 20 lead to the production of polyheads. Observed intracellularly sections, polyheads are tubular structures. The cross sections frequently pentagonal. Polyheads filled with an unidentified internal substance which is different—at least concentration—from contents normal phage. In a lysate most open, but few sealed at one or both ends; open appear empty upon examination. Serological studies show that and heads have antigenic site common. more than To produce polyheads, functions two “head” genes necessary: (a) 23 believed protein subunit capsid, (b) 31, function has not yet been identified. A temperature-sensitive mutation L65 produces abnormal phage heads. This abnormality also observed produced by double mutant tsL65 (in 23) -amN50 20).