Suppressor mutations in Pseudomonas aeruginosa

Abstract

Suppressor mutations of P. aeruginosa were indentified. An isolate of strain PAT, initally selected as being temperature senstiive for growth, suppressed 2 different auxotrophic mutations. A suppressor locus, designated sup-1, was mapped and is co-transducible with 3 closely linked thr loci. The suppressor mutation was used to isolate suppressor-sensitive (sus) mutants of the virulent phage E79 and the R factor R18. By selecting for revertants of auxotrophic markers, other sup mutants were isolated and are of 2 types, either temperature sensitive for growth like the original mutant or showing wild-type growht at 43.degree. C. The mutations giving rise to both these classes of suppressor are very closely linked. One of the sup-1 alleles of strian PAT also shows suppressor activity when transferred into P. aeruginosa strain PA0. Escherichia coli strains carrying the nonsense suppressors supC, supD or supF do not suppress the sus mutant of R18. This suggests that sup-1 is different from the amber and ochre suppressors of the enterobacteria.