Identification of bacteriophage K11 genomic promoters for K11 RNA polymerase.
Only one natural promoter that interacts with bacteriophage K11 RNA polymerase has so far been identified. To identify more, in the present study restriction fragments of the phage genome were individually assayed for transcription activity in vitro. The K11 genome was digested with two 4-bp-recognizing restriction enzymes, and the fragments cloned in pUC119 were assayed with purified K11 RNA polymerase. Eight K11 promoterbearing fragments were isolated and sequenced. We report that the nine K11 promoter sequences (including the one previously identified) were highly homologous from -17 to +4, relative to the initiation site at +1. Interestingly, five had -10G and -8A, while the other four had -10A and -8C. The consensus sequences with the natural -10G/-8A and -10A/-8C, and their variants with -10G/-8C and -10A/-8A, showed nearly equal transcription activity, suggesting residues at -10 and -8 do not regulate promoter activity. Using hybridization methods, physical positions of the cloned promoter-bearing sequences were mapped on SalIand KpnI-restriction maps of the K11 genome. The flanking sequences of six cloned K11 promoters were found to be orthologous with T7 or T3 genomic sequences.
Han
Kyung Goo
KG
Research Center for Bio-Medicinal Resources, Pai-Chai University, Daejeon 302-735, Korea.
Kim
Dong Hee
DH
Junn
Eunsung
E
Lee
Sang Soo
SS
Kang
Changwon
C
D001435:Bacteriophages / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D012321:DNA-Directed RNA Polymerases / Q000235:genetics*; D005814:Genes, Viral; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D014158:Transcription, Genetic
D012321:DNA-Directed RNA Polymerases