Abstract
The large β and β′ subunits of the bacterial core RNA polymerase (RNAP) are highly conserved throughout evolution. Nevertheless, large sequence insertions in β and β′ characterize specific evolutionary lineages of bacteria. The Thermus aquaticus RNAP β′ subunit contains a 283 residue insert between conserved regions A and B that is found in only four bacterial species. The Escherichia coli RNAP β′ subunit contains a 188 residue insert in the middle of conserved region G that is found in a wide range of bacterial species. Here, we present structural studies of these two β′ insertions. We show that the inserts comprise repeats of a previously characterized fold, the sandwich-barrel hybrid motif (as predicted from previous sequence analysis) and that the inserts serve significant roles in facilitating protein/protein and/or protein/nucleic acid interactions.
Original language | English (US) |
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Pages (from-to) | 138-154 |
Number of pages | 17 |
Journal | Journal of Molecular Biology |
Volume | 353 |
Issue number | 1 |
DOIs | |
State | Published - Oct 14 2005 |
All Science Journal Classification (ASJC) codes
- Structural Biology
- Molecular Biology