Related Experiment Videos
Specific polyadenylation and purification of total messenger RNA from Escherichia coli
1Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India.
Abstract:
Obtaining pure mRNA preparations from prokaryotes has been difficult, if not impossible, for want of a poly(A) tail on these messages. We have used poly(A) polymerase from yeast to effect specific polyadenylation of Escherichia coli polysomal mRNA in the presence of magnesium and manganese. The polyadenylated total mRNA, which could be subsequently purified by binding to and elution from oligo(dT) beads, had a size range of 0.4-4.0 kb. We have used hybridization to a specific plasmid-encoded gene to further confirm that the polyadenylated species represented mRNA. Withdrawal of Mg2+ from the polyadenylation reaction resulted in addition of poly(A) to 16S rRNA despite the presence of Mn2+, indicating the vital role of Mg2+ in maintaining the native structure of polysomes. Complete dissociation of polysomes into ribosomal subunits resulted in quantitative polyadenylation of both 16S and 23S rRNA species. Chromosomal lacZ gene-derived messages were quantitatively recovered in the oligo(dT)-bound fraction, as demonstrated by RT-PCR analysis. Potential advantages that accrue from the availability of pure total mRNA from prokaryotes is discussed.
Insights
Researchers developed a method to purify prokaryotic mRNA using yeast poly(A) polymerase. This technique enables the isolation of messenger RNA (mRNA) from bacteria, overcoming previous limitations.
Area of Science:
- Molecular Biology
- Genetics
- Biochemistry
Background:
- Prokaryotic messenger RNA (mRNA) lacks a poly(A) tail, making purification challenging.
- Traditional methods struggle to isolate pure mRNA from prokaryotic sources.
Purpose of the Study:
- To develop a method for purifying prokaryotic mRNA.
- To enable the isolation of bacterial mRNA for downstream applications.
Main Methods:
- Polyadenylation of Escherichia coli polysomal mRNA using yeast poly(A) polymerase.
- Purification of polyadenylated mRNA using oligo(dT) beads.
- Confirmation of mRNA species via hybridization and RT-PCR.
Main Results:
- Successfully polyadenylated and purified prokaryotic mRNA (0.4-4.0 kb).
- Demonstrated the critical role of Mg2+ in maintaining polysome structure during polyadenylation.
- Showed that rRNA is polyadenylated upon polysome dissociation.
Conclusions:
- The developed method allows for the purification of prokaryotic mRNA.
- This technique overcomes a significant hurdle in prokaryotic molecular biology research.
- Pure prokaryotic mRNA can be obtained for various research purposes.