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Antigenic variability of bacterial RNA polymerases
Molecular & General Genetics : MGG
|January 1, 1981
Summary
Bacterial RNA polymerase alpha subunit structure is highly conserved, suggesting evolutionary stability beyond its direct function. This immunological analysis aids in bacterial genealogy, aligning with rRNA-based phylogenies.
Area of Science:
- Microbiology
- Molecular Biology
- Immunology
Background:
- Bacterial RNA polymerase (RNAP) is crucial for gene transcription.
- Understanding RNAP subunit evolution provides insights into bacterial relationships.
- Antigenic structure conservation can reflect functional or evolutionary constraints.
Purpose of the Study:
- To compare the antigenic variability of bacterial RNA polymerase subunits (alpha, beta, beta').
- To investigate the relationship between antigenic structure and functional roles of RNAP subunits.
- To assess the utility of immunological comparisons for bacterial phylogeny reconstruction.
Main Methods:
- Radioimmunoassay (RIA) was used to analyze the antigenic structures of RNAP from various Gram-negative bacteria.
- Antibodies against RNAP subunits were employed to probe antigenic differences and similarities.
- Bacterial genealogies derived from RNAP antigenicity were compared with established phylogenetic trees.
Main Results:
- The alpha subunit's antigenic structure shows significantly lower variability than beta and beta' subunits.
- Surface-exposed antigenic determinants of the alpha subunit are more conserved than internal ones.
- Immunological data largely agree with phylogenetic trees based on 16S and 5S rRNA sequences.
Conclusions:
- The high conservation of the alpha subunit's antigenic structure is not solely dictated by its direct enzymatic function.
- RNAP subunit interactions appear relatively weak, based on variability of internal antigenic determinants.
- Immunological analysis of RNAP is a viable method for bacterial phylogenetic studies, supporting conserved gene evolution.