Premium
On the binding of ATP to the autophosphorylating protein, Ptk, of the bacterium Acinetobacter johnsonii
Author(s) -
Doublet P,
Vincent C,
Grangeasse C,
Cozzone A.J,
Duclos B
Publication year - 1999
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(99)00111-8
Subject(s) - autophosphorylation , biochemistry , biology , bacteria , tyrosine , binding site , adenosine triphosphate , kinase , protein kinase a , genetics
The autophosphorylating protein, Ptk, of the bacterium Acinetobacter johnsonii was overproduced, purified to homogeneity and assayed for ATP binding by using the nucleotide analog 5′‐ p ‐fluorosulfonylbenzoyl adenosine. The ATP binding site of this bacterial autophosphorylating protein was found to be different from that generally used by eukaryotic protein kinases. It consists of two amino acid sequences that closely resemble the Walker motifs A and B. This observation was confirmed by site‐directed mutagenesis experiments which showed, in addition, that the ATP molecule bound to these motifs is effectively employed by the bacterial protein to autophosphorylate on tyrosine. It is concluded that even though the overall autophosphorylation reaction is similar in eukaryotic and prokaryotic proteins, the mechanism involved is likely different.