Sequences required for transcription termination at the intrinsic lambdatI terminator.
The lambdatI terminator is located approximately 280 bp beyond the lambdaint gene, and it has a typical structure of an intrinsic terminator. To identify sequences required for lambdatI transcription termination a set of deletion mutants were generated, either from the 5' or the 3' end onto the lambdatI region. The termination efficiency was determined by measuring galactokinase (galK) levels by Northern blot assays and by in vitro transcription termination. The importance of the uridines and the stability of the stem structure in the termination were demonstrated. The nontranscribed DNA beyond the 3' end also affects termination. Additionally, sequences upstream have a small effect on transcription termination. The in vivo RNA termination sites at lambdatI were determined by S1 mapping and were located at 8 different positions. Processing of transcripts from the 3' end confirmed the importance of the hairpin stem in protection against exonuclease.
Martínez-Trujillo
Miguel
M
Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del I.P.N, México, D.F., México.
Sánchez-Trujillo
Alejandra
A
Ceja
Víctor
V
Avila-Moreno
Federico
F
Bermúdez-Cruz
Rosa María
RM
Court
Donald
D
Montañez
Cecilia
C
D010582:Bacteriophage lambda / Q000235:genetics / Q000502:physiology*; D020029:Base Pairing; D001665:Binding Sites; D015152:Blotting, Northern; D004279:DNA, Viral / Q000235:genetics; D009690:Nucleic Acid Conformation; D017384:Sequence Deletion; D014158:Transcription, Genetic
D004279:DNA, Viral