Compartmentalization of transcription and translation in Bacillus subtilis.
Using fusions of green fluorescent protein to subunits of RNA polymerase (RNAP) and ribosomes, we have investigated the subcellular localization of the transcriptional and translational machinery in the bacterium Bacillus subtilis. Unexpectedly, we found that RNAP resides principally within the nucleoid. Conversely, ribosomes localized almost exclusively outside the nucleoid, concentrating particularly towards sites of cell division. This zonal localization was not dependent on cell division and is probably due, at least in part, to exclusion from the nucleoid. Dual labelling of RNAP and ribosomes was used to confirm the spatial separation of the two processes. We conclude that, even in the absence of a nuclear membrane, transcription and translation occur predominantly in separate functional domains. At higher growth rates, concentrations of RNAP developed, probably representing the sites of rRNA synthesis. These may represent a further spatial specialization, possibly equivalent to the eukaryotic nucleolus.
Lewis
P J
PJ
Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK. plewis@molbiol.ox.ac.uk
Thaker
S D
SD
Errington
J
J
D001412:Bacillus subtilis / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002451:Cell Compartmentation / Q000235:genetics; D017931:DNA Primers / Q000235:genetics; D012321:DNA-Directed RNA Polymerases / Q000235:genetics / Q000378:metabolism; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D014176:Protein Biosynthesis; D012329:RNA, Bacterial / Q000096:biosynthesis; D012335:RNA, Ribosomal / Q000096:biosynthesis; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism; D014158:Transcription, Genetic
D017931:DNA Primers; D008164:Luminescent Proteins; D012329:RNA, Bacterial; D012335:RNA, Ribosomal; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D012321:DNA-Directed RNA Polymerases