title: Phosphate binding in the active centre of tomato multifunctional nuclease TBN1 and analysis of superhelix formation by the enzyme.
abstract: Tomato multifunctional nuclease TBN1 belongs to the type I nuclease family, which plays an important role in apoptotic processes and cell senescence in plants. The newly solved structure of the N211D mutant is reported. Although the main crystal-packing motif (the formation of superhelices) is conserved, the details differ among the known structures. A phosphate ion was localized in the active site of the enzyme. The binding of the surface loop to the active centre is stabilized by the phosphate ion, which correlates with the observed aggregation of TBN1 in phosphate buffer. The conserved binding of the surface loop to the active centre suggests biological relevance of the contact in a regulatory function or in the formation of oligomers.
authors.affiliation: Institute of Biotechnology CAS, v.v.i., Vídeňská 1083, 142 20 Praha 4, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Stránský
authors.affiliation: Institute of Biotechnology CAS, v.v.i., Vídeňská 1083, 142 20 Praha 4, Czech Republic.
authors.forename: Tomáš
authors.initials: T
authors.lastname: Koval'
authors.affiliation: University of Chemistry and Technology, Technická 5, 166 28 Praha 6, Czech Republic.
authors.forename: Tomáš
authors.initials: T
authors.lastname: Podzimek
authors.affiliation: Institute of Plant Molecular Biology, Biology Centre, CAS, v.v.i., Branišovská 31, 370 05 České Budějovice, Czech Republic.
authors.forename: Anna
authors.initials: A
authors.lastname: Týcová
authors.affiliation: University of Chemistry and Technology, Technická 5, 166 28 Praha 6, Czech Republic.
authors.forename: Petra
authors.initials: P
authors.lastname: Lipovová
authors.affiliation: Institute of Plant Molecular Biology, Biology Centre, CAS, v.v.i., Branišovská 31, 370 05 České Budějovice, Czech Republic.
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Matoušek
authors.affiliation: Institute of Biotechnology CAS, v.v.i., Vídeňská 1083, 142 20 Praha 4, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Kolenko
authors.affiliation: Institute of Biotechnology CAS, v.v.i., Vídeňská 1083, 142 20 Praha 4, Czech Republic.
authors.forename: Karla
authors.initials: K
authors.lastname: Fejfarová
authors.affiliation: Institute of Biotechnology CAS, v.v.i., Vídeňská 1083, 142 20 Praha 4, Czech Republic.
authors.forename: Jarmila
authors.initials: J
authors.lastname: Dušková
authors.affiliation: Institute of Biotechnology CAS, v.v.i., Vídeňská 1083, 142 20 Praha 4, Czech Republic.
authors.forename: Tereza
authors.initials: T
authors.lastname: Skálová
authors.affiliation: Institute of Biotechnology CAS, v.v.i., Vídeňská 1083, 142 20 Praha 4, Czech Republic.
authors.forename: Jindřich
authors.initials: J
authors.lastname: Hašek
authors.affiliation: Institute of Biotechnology CAS, v.v.i., Vídeňská 1083, 142 20 Praha 4, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Dohnálek
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites / Q000502:physiology; D003460:Crystallization; D004706:Endodeoxyribonucleases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018551:Solanum lycopersicum / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism*; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017433:Protein Structure, Secondary
chemical_list: D009097:Multienzyme Complexes; D010710:Phosphates; D010940:Plant Proteins; D004706:Endodeoxyribonucleases; C039336:superhelical DNA endonuclease
keywords: TBN1; superhelix; tomato multifunctional nuclease; type I nuclease