Abstract
We have isolated two spontaneous mutations that increase the expression of the Tn9-derived cat gene in Bacillus subtilis. These mutations, which appear to affect initiation of translation of chloramphenicol acetyltransferase (CAT; acetyl-CoA:chloramphenicol 3-O-acetyltransferase, EC 2.3.1.28), consist of a tandem duplication and triplication of a 55-base-pair sequence located at the 5' end of cat. Included in the repeated sequence are the Shine-Dalgarno site, initiation codon, and a region of dyad symmetry located within the structural portion of the cat gene. A striking feature of the mutated initiation sites is their potential to form stem-loop structures at the 5' end of the cat messenger RNA. Within the single-stranded loops of these structures are the ribosome binding site and initiation codon for the cat gene. It appears that the Gram-negative cat translation initiation site has mutated to permit efficient utilization in B. subtilis without directly affecting Shine-Dalgarno sequence homology. This report suggests that secondary structure in the vicinity of the Shine-Dalgarno site can exert a strong positive influence on the initiation of translation in B. subtilis.
Original language | English (US) |
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Pages (from-to) | 173-177 |
Number of pages | 5 |
Journal | Proceedings of the National Academy of Sciences of the United States of America |
Volume | 82 |
Issue number | 1 |
State | Published - 1985 |
ASJC Scopus subject areas
- General
- Genetics