CLONING, NUCLEOTIDE-SEQUENCE, AND TRANSCRIPTIONAL ANALYSIS OF THE NUSG - GENE OF STREPTOMYCES-COELICOLOR A3(2), WHICH ENCODES A PUTATIVE TRANSCRIPTIONAL ANTITERMINATOR

A 3 kb genomic fragment containing the nusG gene of Streptomyces coeli color A3(2) was identified, cloned and sequenced. Sequence analysis re vealed 3 complete and 2 truncated open reading frames (ORFs): truncate d ORF(U) (similar to a Bacillus gene encoding a thermostable aspartate aminotransferase)-secE (94 amino acids; 79.0% similarity to Escherich ia coli SecE)-nusG (300 amino acids; 73.3% similarity to E. coli NusG) -rplK (144 amino acids; 88.5% similarity to E. coli ribosomal subunit L11)-truncated rplA (similar to E. coli ribosomal subunit L1). The gen e organization secE-nusG-rplKA exactly matches that in E. coli. Transc riptional analyses by the primer extension method revealed one transcr iptional start site each for secE and nusG, and two sites for rplK. Th e presence of promoters was also confirmed with the aid of a promoter- probe vector.