Characterization of a eukaryotic type serine/threonine protein kinase and protein phosphatase of Streptococcus pneumoniae and identification of kinase substrates Linda Nova´ kova´ 1, Lenka Saskova´ 1, Petra Pallova´ 1, Jirˇı´ Janecˇek1, Jana Novotna´ 1, Alesˇ Ulrych1, Jose Echenique2, Marie-Claude Trombe3 and Pavel Branny1 1 Cell and Molecular Microbiology Division, Institute of Microbiology, Czech Academy of Sciences, Prague, Czech Republic 2 Departamento de Bioquı´mica Clı´nica, Facultad de Ciencias Quı´micas, Universidad Nacional de Co´ rdoba, Medina Allende esq Haya de la Torre, Ciudad Universitaria, Co´ rdoba, Argentina 3 Centre Hospitalo-Universitaire de Rangueil, Universite´ Paul Sabatier, Toulouse, France Keywords Searching the genome sequence of Streptococcus pneumoniae revealed the phosphoglucosamine mutase; presence of a single Ser ⁄ Thr protein kinase gene stkP linked to protein phosphoproteome; protein phosphatase; phosphatase phpP. Biochemical studies performed with recombinant StkP serine ⁄ threonine protein kinase; suggest that this protein is a functional eukaryotic-type Ser ⁄ Thr protein Streptococcus pneumoniae kinase. In vitro kinase assays and Western blots of S. pneumoniae subcellu- Correspondence lar fractions revealed that StkP is a membrane protein. PhpP is a soluble P. Branny, Cell and Molecular Microbiology protein with manganese-dependent phosphatase activity in vitro against a Division, Institute of Microbiology, Czech synthetic substrate RRA(pT)VA. Mutations in the invariant aspartate resi- Academy of Sciences, Vı´denˇ ska´ 1083, dues implicated in the metal binding completely abolished PhpP activity. 142 20 Prague 4, Czech Republic Autophosphorylated form of StkP was shown to be a substrate for PhpP. Fax: +420 2 41722257 These results suggest that StkP and PhpP could operate as a functional Tel: +420 2 41062658 E-mail:
[email protected] pair in vivo.