LAMBDA-REPRESSED MUTANTS OF BACTERIOPHAGE-T5 .2. PHYSIOLOGICAL CHARACTERIZATION

Physiological properties of bacteriophage T5 gene A1 mutants, whose growth is inhibited in λ lysogens, and designated T5 lr, have been studied. In the presence of λ gene rex, which is responsible for lr growth inhibition, gene A1 product is synthesized and functional. However, several physiological defects were observed: phage DNA synthesis is inhibited; late phage-induced proteins are synthesized in markedly decreased amounts after a delay of about 15 minutes; phage DNA transfer into the host goes beyond the first-step transfer fragment but, in most bacteria, is interrupted after penetration of about 55% of the genome. Relationships between these different defects are discussed. © 1979.