8A0A

Bacillus subtilis SPbeta prophage master regulator MrpR

Summary for 8A0A

• Entry DOI: 10.2210/pdb8a0a/pdb
• Descriptor: Bacillus subtilis SPbeta prophage master regulator MrpR (1 entity in total)
• Functional Keywords: master regulator mrpr of bacillus subtilis spbeta prophage, dna binding protein
• Biological source: Bacillus subtilis subsp. subtilis str. 168
• Total number of polymer chains: 2
• Total formula weight: 77724.75

Authors

Czech, L.,Bange, G. (deposition date: 2022-05-27, release date: 2023-06-14, Last modification date: 2024-05-01)

Primary citation

Kohm, K.,Jalomo-Khayrova, E.,Kruger, A.,Basu, S.,Steinchen, W.,Bange, G.,Frunzke, J.,Hertel, R.,Commichau, F.M.,Czech, L.
Structural and functional characterization of MrpR, the master repressor of the Bacillus subtilis prophage SP beta.
Nucleic Acids Res., 51:9452-9474, 2023

PubMed Abstract: Prophages control their lifestyle to either be maintained within the host genome or enter the lytic cycle. Bacillus subtilis contains the SPβ prophage whose lysogenic state depends on the MrpR (YopR) protein, a key component of the lysis-lysogeny decision system. Using a historic B. subtilis strain harboring the heat-sensitive SPβ c2 mutant, we demonstrate that the lytic cycle of SPβ c2 can be induced by heat due to a single nucleotide exchange in the mrpR gene, rendering the encoded MrpRG136E protein temperature-sensitive. Structural characterization revealed that MrpR is a DNA-binding protein resembling the overall fold of tyrosine recombinases. MrpR has lost its recombinase function and the G136E exchange impairs its higher-order structure and DNA binding activity. Genome-wide profiling of MrpR binding revealed its association with the previously identified SPbeta repeated element (SPBRE) in the SPβ genome. MrpR functions as a master repressor of SPβ that binds to this conserved element to maintain lysogeny. The heat-inducible excision of the SPβ c2 mutant remains reliant on the serine recombinase SprA. A suppressor mutant analysis identified a previously unknown component of the lysis-lysogeny management system that is crucial for the induction of the lytic cycle of SPβ.

PubMed: 37602373
DOI: 10.1093/nar/gkad675

Experimental method

X-RAY DIFFRACTION (2.9 Å)