Structural protein analysis of the polyvalent staphylococcal bacteriophage 812

Abstract

Phage 812 is a polyvalent phage with a very broad host range in the genus Staphylococcus, which makes it a suitable candidate for phage therapy of staphylococcal infections. This proteomic study, combining the results of both 1-DE and 2-DE followed by PMF, led to the identification of 24 virion proteins. Twenty new proteins, not yet identified by proteome analysis of closely related staphylococcal phages K and G1 were identified using this approach. Fifteen proteins were assigned unambiguously to the head-tail genome module; the remaining nine proteins are encoded by genes of the left or right arms of the phage genome. As expected, the most abundant proteins in the electrophoretic patterns are the major capsid protein, the major tail sheath protein and proteins identical to ORF 50 and ORF 95 of phage K, although their function is only putative. Identification of these 20 new proteins contributes substantially to a detailed characterization of phage virions, knowledge of which is necessary for rational phage therapy.

The Terminally Redundant, Nonpermuted Genome ofListeriaBacteriophage A511: a Model for the SPO1-Like Myoviruses of Gram-Positive Bacteria

“…Peptides corresponding to the major capsid (Cps or gp86) and tail sheath (Tsh or gp93) proteins (40) were also found in other bands of lower mass (ϳ45 kDa for Tsh, and ϳ45 kDa and ϳ32 kDa for Cps); possibly due to proteolytic cleavage or degradation. Similar observations were reported for Staphylococcus phage 812 (14), closely related to K. The A511 portal protein (gp83), with a predicted mass of 61.6 kDa, was also found in two bands with significantly lower molecular masses, suggesting posttranslational processing. An unusual finding was that bands 13 and 15 both contain products of orf145, which is not located in the late gene cluster but among genes specifying proteins probably involved in DNA replication and control.…”

Genome of a virulent bacteriophage Lb338-1 that lyses the probiotic Lactobacillus paracasei cheese strain

“…Major caspid (gp109) and structural proteins (gp56 and 113) bands contained more than on protein, possibly due to cleavage or degradation. Presence of more than one band for a given protein was reported previously (Eyer et al, 2007;Klumpp et al, 2008). …”

Romulus and Remus, Two Phage Isolates Representing a Distinct Clade within the Twortlikevirus Genus, Display Suitable Properties for Phage Therapy Applications

“…Mass spectrometric analysis of 20 gel slices of the Remus structural proteome resulted in the identification of 19 proteins (Table 3). Homologs of 18 of these proteins were already identified in earlier proteome studies (11,59), while Gp42 of Remus can now be considered a component of the virus particle as well. Various Remus proteins were detected throughout the SDS-PAGE gel, illustrated by the major capsid (Gp18) and the major tail sheath (Gp25) protein, suggesting their abundant presence in the Remus virion.…”

“…However, band D of Remus is localized several kilodaltons lower. Because for ISP no corresponding molecular mass was found, this band was thought to be a proteolytically processed form of the tail sheath protein (59,60). If this hypothesis is correct, Fig.…”