Control of Bacteriophage T4 Tail Lysozyme Activity During the Infection Process

Journal Article · Mon Jul 19 04:00:00 EDT 2010 · J. Mol. Biol.

DOI:https://doi.org/10.1016/j.jmb.2004.12.042· OSTI ID:1008661

Kanamaru, Shuji; Ishiwata, Yasutaka; Suzuki, Toshiharu; Rossmann, Michael G; Arisaka, Fumio ^[1]

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1. Tokyo I

Bacteriophage T4 has an efficient mechanism for injecting the host Escherichia coli cell with genomic DNA. Its gene product 5 (gp5) has a needle-like structure attached to the end of a tube through which the DNA passes on its way out of the head and into the host. The gp5 needle punctures the outer cell membrane and then digests the peptidoglycan cell wall in the periplasmic space. gp5 is normally post-translationally cleaved between residues 351 and 352. The function of this process in controlling the lysozyme activity of gp5 has now been investigated. When gp5 is over-expressed in E. coli, two mutants (S351H and S351A) showed a reduction of cleavage products and five other mutants (S351L, S351K, S351Y, S351Q, and S351T) showed no cleavage. Furthermore, in a complementation assay at 20 C, the mutants that had no cleavage of gp5 produced a reduced number of plaques compared to wild-type T4. The crystal structure of the non-cleavage phenotype mutant of gp5, S351L, complexed with gene product 27, showed that the 18 residues in the vicinity of the potential cleavage site (disordered in the wild-type structure) had visible electron density. The polypeptide around the potential cleavage site is exposed, thus allowing access for an E. coli protease. The lysozyme activity is inhibited in the wild-type structure by a loop from the adjacent gp5 monomer that binds into the substrate-binding site. The same inhibition is apparent in the mutant structure, showing that the lysozyme is inhibited before gp5 is cleaved and, presumably, the lysozyme is activated only after gp5 has penetrated the outer membrane.

• Research Organization: Advanced Photon Source (APS), Argonne National Laboratory (ANL), Argonne, IL (US)
• Sponsoring Organization: USDOE
• OSTI ID: 1008661
• Journal Information: J. Mol. Biol., Journal Name: J. Mol. Biol. Journal Issue: (4) ; 2005 Vol. 346; ISSN JMOBAK; ISSN 0022-2836
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

36 MATERIALS SCIENCE
BACTERIOPHAGES
CELL MEMBRANES
CELL WALL
CLEAVAGE
CRYSTAL STRUCTURE
DNA
ELECTRON DENSITY
ESCHERICHIA COLI
GENES
LYSOZYME
MONOMERS
MUTANTS
PHENOTYPE
POLYPEPTIDES
RESIDUES