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Publication Abstract from PubMed

The two-component phosphorelay system is the most prevalent mechanism for sensing and transducing environmental signals in bacteria. Spore formation, which relies on the two-component phosphorelay system, enables the longterm survival of the glacial bacterium Paenisporosarcina sp. TG-14 in the extreme cold environment. Spo0A is a key response regulator of the phosphorelay system in the early stage of spore formation. The protein is composed of a regulatory N-terminal phospho-receiver domain and a DNAbinding C-terminal activator domain. We solved the threedimensional structure of the unphosphorylated (inactive) form of the receiver domain of Spo0A (PaSpo0A-R) from Paenisporosarcina sp. TG-14. A structural comparison with phosphorylated (active form) Spo0A from Bacillus stearothermophilus (BsSpo0A) showed minor notable differences. A molecular dynamics study of a model of the active form and the crystal structures revealed significant differences in the alpha4 helix and the preceding loop region where phosphorylation occurs. Although an oligomerization study of PaSpo0A-R by analytical ultracentrifugation (AUC) has shown that the protein is in a monomeric state in solution, both crosslinking and crystal-packing analyses indicate the possibility of weak dimer formation by a previously undocumented mechanism. Collectively, these observations provide insight into the mechanism of phosphorylation-dependent activation unique to Spo0A.

Crystal structure of the inactive state of the receiver domain of Spo0A from Paenisporosarcina sp. TG-14, a psychrophilic bacterium isolated from an Antarctic glacier.,Lee CW, Park SH, Lee SG, Shin SC, Han SJ, Kim HW, Park HH, Kim S, Kim HJ, Park H, Park H, Lee JH J Microbiol. 2017 Mar 9. doi: 10.1007/s12275-017-6599-9. PMID:28281198^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.