title: Isolation and characterization of the bacteriophage T4 tail-associated lysozyme.
abstract: Direct evidence has been obtained that the tail-associated lysozyme of bacteriophage T4 (tail-lysozyme) is gp5, which is a protein component of the hub of the baseplate. Tails were treated with 3 M guanidine hydrochloride containing 1% Triton X-100, and the tail-lysozyme was separated from other tail components by preparative isoelectric focusing electrophoresis as a peak with a pI of 8.4. The molecular weight as determined from sodium dodecyl sulfate electrophoresis was 42,000. The tail-lysozyme was unambiguously identified as gp5 when the position of the lysozyme was compared with that of gp5 of tube-baseplates from 5ts1/23amH11/eL1ainfected Escherichia coli cells by two-dimensional gel electrophoresis. The tail-lysozyme has N-acetylmuramidase activity and the same substrate specificity as gene e lysozyme; the optimum pH is around 5.8, about 1 pH unit lower than for the e lysozyme. We assume that the tail-lysozyme plays an essential role in locally digesting the peptidoglycan layer to let the tube penetrate into the periplasmic space. The tail-lysozyme is presumably also responsible for "lysis from without."
authors.forename: H
authors.initials: H
authors.lastname: Nakagawa
authors.forename: F
authors.initials: F
authors.lastname: Arisaka
authors.forename: S
authors.initials: S
authors.lastname: Ishii
mesh_terms: D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D009113:Muramidase / Q000302:isolation & purification* / Q000502:physiology; D009154:Mutation; D013379:Substrate Specificity; D013604:T-Phages / Q000201:enzymology*; D014764:Viral Proteins / Q000032:analysis*; D017376:Viral Tail Proteins
chemical_list: D014764:Viral Proteins; D017376:Viral Tail Proteins; D009113:Muramidase