Suppression of TGA mutations in the Bacillus subtilis spoIIR gene by prfB mutations.
J Bacteriol
; 180(16): 4166-70, 1998 Aug.
Article
in En
| MEDLINE
| ID: mdl-9696765
ABSTRACT
An unexpectedly high proportion of TGA nonsense mutations was obtained in a collection of chemically induced mutations in the spoIIR locus of Bacillus subtilis. Of 11 different mutations obtained, TGA mutations were found in four codons, whereas only three codons yielded missense mutations. Six suppressors of the TGA mutations were isolated, and five of the suppressing mutations were mapped to the prfB gene encoding protein release factor 2. These are the first mutations shown to map to the B. subtilis prfB locus. The sequence of the prfB gene was completed, and two revisions of the published sequence were made. The five prfB mutations also resulted in suppression of the catA86-TGA mutation to between 19 and 54% of the expression of catA86(+), compared to the readthrough level of 6% in the prfB+ strain. N-terminal sequencing of suppressed catA86-TGA-specified protein demonstrated that the amino acid inserted at UGA because of the prfB1 mutations was tryptophan.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Sigma Factor
/
Suppression, Genetic
/
Bacillus subtilis
/
Bacterial Proteins
/
Transcription Factors
/
Codon, Terminator
Language:
En
Journal:
J Bacteriol
Year:
1998
Document type:
Article
Affiliation country:
United States