Poly (A) RNA in Bacillus subtilis: Identification of the polyadenylylation site of flagellin mRNA

Using improved procedures for the synthesis, amplification, and cloning of DNA complementary to bacterial poly(A) RNA, we succeeded in deducing the 3′‐terminal sequence of polyadenylylated flagellin mRNA encoded by the Bacillus subtilis hag gene. The site of polyadenylylation was found to be just upstream of the terminal stem‐loop structure corresponding to the putative rho‐independent transcription terminator of the hag gene. This corresponds to the major polyadenylation site of Escherichia coli lipoprotein (lpp) mRNA [G.C. Gao and N. Sarkar (1992) Proc. Natl. Acad. Sci. USA 89, 7546–7550], suggesting that the primary transcript is processed by endonucleolytic cleavage prior to polyadenylylation in Gram‐positive as well as in Gram‐negative bacteria.