STRUCTURE AND NUCLEOTIDE-SEQUENCE OF THE BACILLUS-SUBTILIS PHENYLALANYL-TRANSFER RNA-SYNTHETASE GENES

The nucleotide sequence of the Bacillus subtilis pheST genes coding for the 2 subunits of phenylalanyl-tRNA synthetase has been determined. The pheS gene corresponds to 1029 bp and the pheT gene to 2412 bp. The encoded proteins have M(r)s of 38 947 (343 amino acids, alpha-subunit) and 87 916 (804 amino acids, Beta-subunit), respectively. The genes are adjacent on the chromosome separated by only 15 nucleotides. The pheT gene is immediately followed by a hairpin structure typical of a rho-independent transcription terminator. S1 nuclease mapping and primer extension analysis of pheST mRNA revealed a major start of transcription 318 nucleotides upstream of the pheS gene, and 6 nucleotides downstream of a E-sigma-43 promoter consensus sequence. Within the 5'-noncoding region several potential secondary structures have been noted.