Bacteriophage lysozyme

A T4 bacteriophage lysozyme (from phage grown on Eco/ZB ) [12585-29-4] was extracted and freed from... 

Grutter, M.G., L.H. Weaver, and B.W. Mattews. 1983. Goose lysozyme structure An evolutionary link between hen and bacteriophage lysozyme. Nature 303 828-831. 

Salser, W., Gesteland, R. F., Bolle, A. In vitro synthesis of bacteriophage lysozyme. Nature (Lond.) 215, 588-591 (1967). 

Lysozyme from bacteriophage T4 is a 164 amino acid polypeptide chain that folds into two domains (Figure 17.3) There are no disulfide bridges the two cysteine residues in the amino acid sequence, Cys 54 and Cys 97, are far apart in the folded structure. The stability of both the wild-type and mutant proteins is expressed as the melting temperature, Tm, which is the temperature at which 50% of the enzyme is inactivated during reversible beat denat-uration. For the wild-type T4 lysozyme the Tm is 41.9 °C. 

We have already seen the diversity of function in the lyases, hydrolases and oxidoreductases. Several other types of zinc coordination are found in a number of other enzymes, illustrated in Figure 12.8. These include enzymes with the coordination motif [(His)2(Cys) Zn2+-OH2], illustrated by the lysozyme of bacteriophage T7 this group also includes a peptidyl deformylase. 

Figure 12.8 Some other active-site coordination motifs in mononuclear zinc enzymes from left to right bacteriophage T7 lysozyme, 5-aminolaevulinate dehydratase, Ada DNA repair protein. (Reprinted with permission from Parkin, 2004. Copyright (2004) American Chemical Society.)...

Many bacterial enzymes and proteins, which are modified by the introduction of F-Phe or F-Tryp, have been obtained. Mammalian proteins containing F-Pro or other fluorinated amino acids have also been obtained, either in a direct manner in vivo) or, more efficiently, by the expression of the gene in a bacteria. Thus, trifluoro-methionine has been incorporated by E. coli in the lysozyme of a bacteriophage. Because this enzyme contains three methionines, it has been used to study the interactions of this protein with its ligands by F NMR. ... 

Lysozyme is an enzyme that hydrolyzes some bacterial cell-walls, the bacterium used for the assay being Micrococcus lysodeikticus. Lysozyme is found in a wide variety of species and locations, including bacteriophages, blood, egg white, gastric secretions, milk, nasal mucus, papaya, sputum, and tears. The outstanding achievement in this field has been the elucidation of the crystal structures of some of the lysozyme-substrate complexes. 

Water arrangements essentially similar to those for lysozyme have been found for various other high-resolution structures of proteins, for example, penicillopepsin (James and Sielecki, 1983), ferricytochrome c (Finzel et al., 1985), glyceraldehyde-3-phosphate dehydrogenase (Skar-zynski et al., 1987), and bacteriophage T4 lysozyme (Weaver tuid Matthews, 1987). Wlodawer et al. (1988) described the solvent about phosphate-free ribonuclease A, at 1.26 A, and have compared their results with those for other high-resolution structures of this protein. 

The egg white of the Australian black swan, Cygrms atratus, contains two forms of lysozyme c and g types. The X-ray structure of the g type has been determined by Isaacs etal. (1985) at 0.28-nm (2.8 A) resolution. A comparison of the structures of chicken egg white, goose egg white (g type), and bacteriophage T4 types of lysozyme has been made by Weaver et al. (1985), and the evolutionary relationships have been discussed in light of this study. This work is discussed in Section X. 

Weaver et al. (1985) noted some similarities in the active site of the three lysozymes, but with the following striking difference. Residue 73 (Glu) in goose corresponds with residue 35 (Glu) in chick and with residue 11 (Glu) in bacteriophage T4. On the other hand, there are two Asp residues at positions 86 and 97 in the goose active site, neither of which corresponds exactly with Asp-52 of chick nor Asp-20 of T4. The implications for potential differences in the mechanism of catalytic action by the three lysozymes were discussed by Johnson et al. (1988) and by et al. (1985). The latter authors discussed the unresolved question as to whether the c-type lysozyme exons correspond to distinct structural and/or functional entities that are conserved during evolution of the three types of lysozyme considered. 

In addition to the variations of the GT-A and GT-B fold described above for sialyltransferases (7, 8) and fucosyltrans-ferases (17), a distinct GT-C fold family has been predicted for GTs that use lipid linked donors. The crystal structures of the GT domain of the peptidoglycan glycosyltransferase from Staphylococcus aureus (18) (Fig. 3f) and Aquifex aeolicus, (26) show structural similarity to the bacteriophage k-lysozyme. These novel structures demonstrate the possibility of additional folds. 

Hurley JH, Baase WA, Matthews BW. Design and structural analysis of alternative hydrophobic core packing arrangements in bacteriophage T4 lysozyme. J. Mol. Biol. 1992 224 1143-1159. 44. 

Fig. 14. Effects of replacement by Ala of the indicated residues in the synthetic loop peptide of lysozyme on ability to inhibit inactivation by antiloop antibodies of bacteriophage-loop conjugate. From Amon et and Teicher et al. ...

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