A supressor of non sense mutations in Bacillus subtilis

Abstract

The suppressor-sensitive mutants of phage φ29, susB47 and susN212, do not induce the synthesis of proteins NP1 and II, respectively, when they infect Bacillus subtilis su−. A new polypeptide of molecular weight 75000, smaller than that of protein NP1, is produced in susB47-infected cells. An analysis of the methionine-containing tryptic peptides of protein NP1 and the 75000-molecular-weight polypeptide showed that both proteins are related. When mutants susB47 and susN212 infect B. subtilissu+3, a small amount of proteins NP1 and II, respectively, is synthesized, the level of the suppression being about 10%. The results indicate that the B. subtilis su+3 strain is a suppressor of nonsense mutations.