Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.1.1.113 (restriction-modification system)
 350 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Plaque formation of phage kappa on Serratia marcescens strain HY normally depends on the presence of either a psi or y prophage in the indicator bacteria. Bacterial ink mutants allowing kappa growth in the absence of either prophage were isolated from the doubly cured strain HY (psi, y)--. By means of a kappa mutant, named gdy, an active participation of kappa in antagonizing inhibition of its own growth on HY (psi, y)-- was demonstrated. The gdy mutation is closely linked to gene cIII coding for the kappa repressor. The prophages psi and y enable kappa to grow undisturbed probably by modifying the kappa DNA during replication in such a way that it is not susceptible to the ink+ effect. Whereas kappa grown on HY (psi, y)--ink-- gave only rare productive infections of HY (kappa, y)--, psi and y grown on the same strain were fully infective. The interference exerted by a kappa prophage on vegetative propagation of y is based upon a multi-component mechanism, the interference being removed, or diminished by mutations residing either inside or outside of the kappa prophage. The responsive phage gene iny+ is dominant over its mutant allele iny--; hence it codes for a diffusible product. Both on the vegetative and the prophage genome iny is located near gene lI responsible for lysogenic conversion of bacteria to non-adsorption of kappa. The restriction-modification system of HY is not involved in the growth inhibition of kappa by HY (psi, y)--. Contrary to the other phages used in this work y is refractory to restriction.
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PMID:Genetic analysis of prophage effects on heteroimmune superinfection in Serratia marcescens. 702 39