Tale of tails; structural comparison of the RNA polymerase δ-subunits
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| Year of publication | 2024 |
| Type | Conference abstract |
| MU Faculty or unit | |
| Citation | |
| Description | The ?-subunit of prokaryotic RNA polymerase is an integral part of the transcription machinery of many Gram-positive bacteria from the phylum Firmicutes. It was demonstrated that it plays critical role in the regulation of the stress responses, environmental adaptation, sporulation and virulence of several important pathogens, such as Staphylococcus aureus and Streptococcus spp. (1,2). It plays different roles in transcription; its part in the transcription termination and the RNA polymerase complex recycling was recently well described (3). On the other hand, the exact mechanism of function during the transcription initiation are still not fully understood. In the past, our group was able to solve the structure of ?-subunit from Bacillus subtilis. The ~20 kDa protein is comprised of a structured N-terminal domain (NTD) and a negatively charged and poorly conserved C-terminal domain (CTD), with an exception of the well-conserved lysine tract at the beginning of the CTD. We previously demonstrated, that the negatively charged CTD transiently interacts with the lysines, leading to a more compacted structure of the ?-subunit (4). However, some of the Firmicutes, such as S. aureus, are missing the lysine tract which is instead located on the RNA polymerase core. In this poster, we designed purification protocols to obtain pure samples of both proteins and their respective mutants (devoid or with lysine tract included) from B. subtilis and S. aureus. We then compared their structural properties by means of circular dichroism spectroscopy (CD), small-angle X-ray scattering (SAXS) and nuclear magnetic resonance spectroscopy (NMR) to probe the importance of the lysine tract for the global structure of ?-subunit. |
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