STRUCTURAL BIOLOGY APPROACH TO study the SPORULATION PROCESS
Imrich Barák1*, Anthony J. Wilkinson2, Katarína Muchová1,
Patrik Florek1, Zuzana Chromiková1
1 Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava 45, Slovakia;
* Corresponding author: phone: ++421 2 5930 7418, fax: ++421 2 5930 7416, e-mail: email@example.com
Bacillus subtilis is a model organism for the study of one of the simplest cell differentiation process, called sporulation. A rich amount of genetic, biochemical and molecular biology data have been obtained during the study of this process. Recently, this study has advanced to the solving the tertiary structure of key protein regulators. This contribution focuses on the progress in protein crystallography oriented toward the understanding of sporulation mechanisms, that have been achieved in the last couple of years.
The phosphorelay is the main regulatory network in the initation of sporulation. Recently, the tertiary structures some of the components of this network were solved. The structures of response regulators Spo0F , Spo0A [2,3,4] and phosphotransferase Spo0B , together with biochemical and mutational data provide an important framework for further understanding of their biological function at the molecular level.
Structural data were also obtained from some proteins involved in activation of the first cell-type specific s factor - sF (structures of anti-anti-s factor SpoIIAA and anti-s factor SpoIIAB in the complex with sF) [6,1].
The structures of only a small number from more than 100 sporulation specific proteins are known due to problems associated with the crystallization of these proteins. Structures for many of the interesting candidates remain a challenge. Among them are the membrane bound proteins and proteins with highly flexible domains.
Especially interesting for understanding of the mechanism of the transient gene expression asymmetry during sporulation would be the detailed study of sporulation septa formation by solving the crystal structure of key proteins involved in this cell division and chromosome translocation processes such as phosphatase SpoIIE, DNA translocase SpoIIIE or division protein DivIVA.
Work in authors laboratories is supported by grant 2/1004/22 from the Slovak Academy of Sciences and Wellcome Trust Project and Collaborative Research Initiative Grants (056247/Z/98/Z and 066732/Z/01/Z, respectively).
1. E. A. Campbell, S. Masuda, J. L. Sun, O. Muzzin, C. A. Olson, S. Wang & S. A. Darst, Cell, 108 (2002) 795-807.
2. R. J. Lewis, J. A. Brannigan, K. Muchová, I. Barák & A. J. Wilkinson, J. Mol. Biol., 294 (1999) 9-15.
3. R. J. Lewis, K. Muchová, J. A. Brannigan, I. Barák, G. Leonard & A. J. Wilkinson, J. Mol. Biol., 297 (2000) 757-770.
4. R. J. Lewis, S. Krzywda, J. A. Brannigan, J. P. Tukenburg, K. Muchová, E. J. Dodson, I. Barák & A. J. Wilkinson, Mol. Microbiol., 38 (2000) 198-212.
5. Madhusudan, J. Zapf, J. M.Whiteley, J. A.Hoch, N. H. Xuong & K. I. Varughese, Structure, 4(1996) 679-690.
6. P. R. Seavers, R. J. Lewis, J. A. Brannigan, K. H. G. Verschueren, G. N. Murshudov & A. J. Wilkinson, Structure, 9 (2001) 614–615.
7. K. I. Varughese, Madhusudan, X. Z. Zhou, J. M. Whiteley & J. A. Hoch, Mol. Cell, 2 (1998) 485-493.