The role of side tail fibers during the infection cycle of phage lambda

Bacteriophage λ has served as an important model for molecular biology and different cellular processes over the past few decades. In 1992, the phage strain used in most laboratories around the world, thought of as λ wild type, was discovered to carry a mutation in the stf gene which encodes four side tail fibers. Up to now, the role of the side tail fibers during the infection cycle, especially at the single-cell level, remains largely unknown. Here we utilized fluorescent reporter systems to characterize the effect of the side tail fibers on phage infection. We found that the side tail fibers interfere with phage DNA ejection process, most likely through the binding with their receptors, OmpC, leading to a more frequent failed infection. However, the side tail fibers do not seem to affect the lysis-lysogeny decision-making or lysis time.