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Single-step Purification of Macromolecular Complexes Using RNA Attached to Biotin and a Photo-cleavable Linker
Published on: January 3, 2019
Molecular architecture of the human pre-mRNA 3' processing complex.
Yongsheng Shi1, Dafne Campigli Di Giammartino, Derek Taylor
1Department of Biological Sciences, Columbia University, New York, NY 10027, USA.
Molecular Cell
|February 17, 2009
Summary
Researchers purified and characterized human mRNA 3' processing complexes, revealing approximately 85 proteins and a distinct molecular architecture. This finding deepens our understanding of gene expression and posttranscriptional control.
Area of Science:
- Molecular Biology
- Gene Expression Regulation
Background:
- Pre-messenger RNA (mRNA) 3' end formation is crucial for eukaryotic gene expression.
- Alternative polyadenylation in over half of human genes highlights its role in posttranscriptional gene control.
- The complete protein composition and structure of mammalian mRNA 3' processing machinery remain largely unknown.
Purpose of the Study:
- To purify and characterize the protein composition and molecular architecture of human mRNA 3' processing complexes.
- To identify known and novel factors involved in mRNA 3' end formation.
- To elucidate the structural features of the mRNA 3' processing machinery.
Main Methods:
- Purification of human mRNA 3' processing complexes.
- Proteomic analysis to identify constituent proteins.
- Structural characterization using electron microscopy.
Main Results:
- Purified complexes contain approximately 85 proteins, including known and novel core processing factors.
- Over 50 identified proteins may mediate crosstalk with other cellular processes.
- Electron microscopy revealed a distinct "kidney" shape, approximately 250 angstroms in length.
Conclusions:
- The study reveals the intricate complexity and molecular architecture of the human mRNA 3' processing complex.
- This provides a foundation for understanding the regulation of mRNA 3' end formation.
- The findings offer insights into the mechanisms of posttranscriptional gene control.
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Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a “cap” to the 5’ end of the growing transcript. In this process, a 5’ phosphate is replaced by modified guanosine that has a methyl group attached to it (7-Methyl guanosine). This 5’ cap helps the...
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