| Title | 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 |
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| Author | Chang Woo Lee1,2, Sun-Ha Park1, Sung Gu Lee1,2, Seung Chul Shin1, Se Jong Han2,3, Han-Woo Kim1,2, Hyun Ho Park4, Sunghwan Kim5, Hak Jun Kim6, Hyun Park1,2, HaJeung Park7*, and Jun Hyuck Lee1,2* |
| Address | 1Unit of Polar Genomics, Korea Polar Research Institute, Incheon 21990, Republic of Korea, 2Department of Polar Sciences, Korea University of Science and Technology, Incheon 21990, Republic of Korea, 3Division of Life Sciences, Korea Polar Research Institute, Incheon 21990, Republic of Korea, 4Department of Biochemistry, School of Biotechnology and Graduate School of Biochemistry, Yeungnam University, Gyeongsan 38541, Republic of Korea, 5New Drug Development Center, Daegu-Gyungpook Medical Innovation Foundation, Daegu 41061, Republic of Korea, 6Department of Chemistry, Pukyong National University, Busan 608-739, Republic of Korea, 7X-Ray Core, TRI, The Scripps Research Institute, Jupiter, FL 33458, USA |
| Bibliography | Journal of Microbiology, 55(6),464-474, 2017, |
| DOI | 10.1007/s12275-017-6599-9 |
| Key Words | nalytical ultracentrifugation, Paenisporosarcina sp. TG-14, spore formation, Spo0A, X-ray crystallography |
| Abstract | The two-component phosphorelay system is the most pre-valent mechanism for sensing and transducing environ-mental signals in bacteria. Spore formation, which relies on the two-component phosphorelay system, enables the long- term survival of the glacial bacterium Paenisporosarcina sp. TG-14 in the extreme cold environment. Spo0A is a key re-sponse regulator of the phosphorelay system in the early stage of spore formation. The protein is composed of a regu-latory N-terminal phospho-receiver domain and a DNA- binding C-terminal activator domain. We solved the three- dimensional 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 stearo-thermophilus (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 α4 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 me-chanism of phosphorylation-dependent activation unique to Spo0A. |