The Pto bacterial resistance gene and the Fen insecticide sensitivity gene encode functional protein kinases with serine/threonine specificity.
The catalytic activity and amino acid specificity of the tomato Pto and Fen kinases were investigated. The Pto and Fen genes were fused to the carboxyl terminus of the maltose-binding protein and expressed in Escherichia coli. Incubation of the purified fusion proteins with [gamma-32P]ATP in an in vitro assay showed that both proteins were capable of autophosphorylation. Mutant fusion proteins in which the conserved lysine residue of subdomain II was changed to a glutamine were unable to autophosphorylate. Phosphoamino analysis of the active fusion proteins indicated that both kinases phosphorylate serine and threonine residues but not tyrosine.
Loh
Y T
YT
Department of Agronomy, Purdue University, West Lafayette, Indiana 47907-1150, USA.
Martin
G B
GB
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D001483:Base Sequence; D017124:Conserved Sequence; D005284:Fenthion / Q000494:pharmacology; D017343:Genes, Plant / Q000235:genetics*; D007113:Immunity, Innate / Q000235:genetics; D018551:Solanum lycopersicum / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000382:microbiology; D008969:Molecular Sequence Data; D010766:Phosphorylation; D010935:Plant Diseases / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
D000596:Amino Acids; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; D005284:Fenthion; C091599:Fen protein, Lycopersicon esculentum; C084354:Pto protein, Lycopersicon; D017346:Protein Serine-Threonine Kinases