The hybrid histidine kinase Slr1759 of the cyanobacterium Synechocystis sp. PCC 6803 contains FAD at its PAS domain.
The cyanobacterium Synechocystis sp. PCC 6803 harbours 47 histidine kinases (Hiks). Among these are hybrid histidine kinases with one or two response regulator domains as well as numerous Hiks with several sensory domains. One example is the hybrid histidine kinase Slr1759 (Hik14) that has two PAS domains arranged in tandem linked to a predicted GAF domain. Here, we show that a Slr1759 derivative recombinantly expressed in Escherichia coli has a flavin cofactor. Using truncated Slr1759 variants, it is shown that the flavin associates with the first PAS domain. The cofactor reconstitutes the activity of D: -amino acid oxidase apoprotein from pig kidney, indicating that the flavin derivative is FAD. Furthermore, the Slr1759 histidine kinase domain indeed undergoes autophosphorylation in vitro. The phosphorylated product of a recombinant Slr1759 derivative is sensitive to acids, pointing to a histidine residue as the phosphate-accepting group.
Department of Molecular Cell Physiology, University of Bielefeld, Bielefeld, Germany.
Klaus-Peter
KP
Michel
Ann-Kristin
AK
Schröder
Maike
M
Zimmermann
Sonja
S
Brandt
Elfriede K
EK
Pistorius
Nicole
N
Frankenberg-Dinkel
Dorothee
D
Staiger
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D005182:Flavin-Adenine Dinucleotide / Q000378:metabolism*; D006639:Histidine / Q000378:metabolism; D000071677:Histidine Kinase; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity; D046939:Synechocystis / Q000201:enzymology* / Q000235:genetics; D045725:Tetrapyrroles / Q000378:metabolism
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D011994:Recombinant Proteins; D045725:Tetrapyrroles; D005182:Flavin-Adenine Dinucleotide; D006639:Histidine; D011494:Protein Kinases; D000071677:Histidine Kinase