Catalytic roles of lysines (K9, K27, K31) in the N-terminal domain in human adenylate kinase by random site-directed mutagenesis.
To elucidate lysine residues in the N-terminal domain of human cytosolic adenylate kinase (hAK1, EC 2.7.4.3), random site-directed mutagenesis of K9, K27, and K31 residues was performed, and six mutants were analyzed by steady-state kinetics. K9 residue may play an important role in catalysis by interacting with AMP2-. K27 and K31 residues appear to play a functional role in catalysis by interacting with MgATP2-. In human AK, the epsilon-amino group in the side chain of these lysine residues would be essential for phosphoryl transfer between MgATP2- and AMP2- during transition state.
Ayabe
T
T
Department of Hygiene, Miyazaki Medical College, Japan.
Park
S K
SK
Takenaka
H
H
Sumida
M
M
Uesugi
S
S
Takenaka
O
O
Hamada
M
M
D000249:Adenosine Monophosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000263:Adenylate Kinase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D002384:Catalysis; D006801:Humans; D007700:Kinetics; D008239:Lysine / Q000378:metabolism*; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D011487:Protein Conformation
D000249:Adenosine Monophosphate; D000255:Adenosine Triphosphate; D000263:Adenylate Kinase; D008239:Lysine