The Escherichia coli FKBP-type PPIase SlyD is required for the stabilization of the E lysis protein of bacteriophage phi X174.
Most bacteriophages abruptly terminate their vegetative cycle by causing lysis of the host cell. The ssDNA phage phi X174 uses a single lysis gene, E, encoding a 91-amino-acid membrane protein that causes lysis of Escherichia coli by inhibiting MraY, a conserved enzyme of murein biosynthesis. Recessive mutations in the host gene slyD (sensitivity to lysis) absolutely block E-mediated lysis and phi X174 plaque formation. The slyD gene encodes a FKBP-type peptidyl-prolyl cis-trans isomerase ( PPIase). To investigate the molecular basis of this unique FKBP-dependence, spontaneous plaque-forming mutants of phi X174 were isolated on a slyD lawn. All of these Epos ('plates on slyD') suppressors encode proteins with either a R3H or L19F change. The double mutant was also isolated and generated the largest plaques on the slyD lawn. A c-myc epitope tag sequence was incorporated into the parental E and Epos genes without effect on lytic function. Western blots and pulse-chase labelling experiments showed that both Epos and E are highly unstable in a slyD background; however, Epos is synthesized at a higher rate, allowing a lysis-sufficient level of Epos to accumulate. Our results indicate that SlyD is required for stabilizing the E protein and allowing it to accumulate to the levels required to exert its lytic effect. These data are discussed in terms of a model for the specific role of the SlyD PPIase in E folding, and of the use of the very strict SlyD- dependence phenotype for identifying elements of PPIase selectivity.[1]References
- The Escherichia coli FKBP-type PPIase SlyD is required for the stabilization of the E lysis protein of bacteriophage phi X174. Bernhardt, T.G., Roof, W.D., Young, R. Mol. Microbiol. (2002) [Pubmed]
Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenesOpen Access LicencePrivacy PolicyTerms of Useapsburg
