Evidence of bar minigene expression and tRNA2Ile sequestration as peptidyl-tRNA2Ile during lambda bacteriophage development.
Lambda bacteriophage development is impaired in Escherichia coli cells defective for peptidyl (pep)-tRNA hydrolase (Pth). Single-base-pair mutations (bar(-)) that affect translatable two-codon open reading frames named bar minigenes (barI or barII) in the lambda phage genome promote the development of this phage in Pth-defective cells (rap cells). When the barI minigene is cloned and overexpressed from a plasmid, it inhibits protein synthesis and cell growth in rap cells by sequestering tRNA(2)(Ile) as pep-tRNA(2)(Ile). Either tRNA(2)(Ile) or Pth may reverse these effects. In this paper we present evidence that both barI and barII minigenes are translatable elements that sequester tRNA(2)(Ile) as pep-tRNA(2)(Ile). In addition, overexpression of the barI minigene impairs the development even of bar(-) phages in rap cells. Interestingly, tRNA or Pth may reestablish lambda phage development. These results suggest that lambda bar minigenes are expressed and tRNA(2)(Ile) is sequestered as pep-tRNA(2)(Ile) during lambda phage development.
Departamento de Genética y Biología Molecular, CINVESTAV-IPN, San Pedro Zacatenco, Mexico D.F. 07360, Mexico.
Norma Angélica
NA
Oviedo de Anda
Luis
L
Kameyama
José Manuel
JM
Galindo
Gabriel
G
Guarneros
Javier
J
Hernandez-Sanchez
D010582:Bacteriophage lambda / Q000235:genetics* / Q000254:growth & development*; D002265:Carboxylic Ester Hydrolases / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism / Q000821:virology*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D005814:Genes, Viral; D009154:Mutation; D016366:Open Reading Frames; D014176:Protein Biosynthesis; D012346:RNA, Transfer, Amino Acyl / Q000096:biosynthesis / Q000378:metabolism*; D012355:RNA, Transfer, Ile / Q000378:metabolism*
D029968:Escherichia coli Proteins; D012346:RNA, Transfer, Amino Acyl; D012355:RNA, Transfer, Ile; C019037:tRNA, peptidyl-; D002265:Carboxylic Ester Hydrolases; C019674:aminoacyl-tRNA hydrolase