Cdk1 is a small protein (approximately 34 kilodaltons), and is highly conserved.
 The human homolog of Cdk1, CDC2, shares approximately 63% amino-acid identity with its yeast homolog.
Furthermore, human CDC2 is capable of rescuing fission yeast carrying a cdc2 mutation.
 Cdk1 is comprised mostly by the bare protein kinase motif, which other protein kinases share.
 Cdk1, like other kinases, contains a cleft in which ATP fits.
 Substrates of Cdk1 bind near the mouth of the cleft, and Cdk1 residues catalyze the covalent bonding of the γ-phosphate to the oxygen of the hydroxyl serine/threonine of the substrate.

In addition to this catalytic core, Cdk1, like other cyclin-dependent kinases, contains a T-loop, which, in the absence of an interacting cyclin, prevents substrate binding to the Cdk1 active site.
 Cdk1 also contains a PSTAIRE helix, which, upon cyclin binding, moves and rearranges the active site, facilitating Cdk1 kinase activities.
Cdk1 is a small protein (approximately 34 kilodaltons), and is highly conserved.  The human homolog of Cdk1, CDC2, shares approximately 63% amino-acid identity with its yeast homolog. Furthermore, human CDC2 is capable of rescuing fission yeast carrying a cdc2 mutation.  Cdk1 is comprised mostly by the bare protein kinase motif, which other protein kinases share.  Cdk1, like other kinases, contains a cleft in which ATP fits.  Substrates of Cdk1 bind near the mouth of the cleft, and Cdk1 residues catalyze the covalent bonding of the γ-phosphate to the oxygen of the hydroxyl serine/threonine of the substrate.
In addition to this catalytic core, Cdk1, like other cyclin-dependent kinases, contains a T-loop, which, in the absence of an interacting cyclin, prevents substrate binding to the Cdk1 active site.  Cdk1 also contains a PSTAIRE helix, which, upon cyclin binding, moves and rearranges the active site, facilitating Cdk1 kinase activities.
Cyclin-dependent kinase 1