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PDBsum entry 1b39
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Contents |
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* Residue conservation analysis
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References listed in PDB file
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Key reference
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Title
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Effects of phosphorylation of threonine 160 on cyclin-Dependent kinase 2 structure and activity.
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Authors
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N.R.Brown,
M.E.Noble,
A.M.Lawrie,
M.C.Morris,
P.Tunnah,
G.Divita,
L.N.Johnson,
J.A.Endicott.
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Ref.
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J Biol Chem, 1999,
274,
8746-8756.
[DOI no: ]
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PubMed id
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Abstract
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We have prepared phosphorylated cyclin-dependent protein kinase 2 (CDK2) for
crystallization using the CDK-activating kinase 1 (CAK1) from Saccharomyces
cerevisiae and have grown crystals using microseeding techniques.
Phosphorylation of monomeric human CDK2 by CAK1 is more efficient than
phosphorylation of the binary CDK2-cyclin A complex. Phosphorylated CDK2
exhibits histone H1 kinase activity corresponding to approximately 0.3% of that
observed with the fully activated phosphorylated CDK2-cyclin A complex.
Fluorescence measurements have shown that Thr160 phosphorylation increases the
affinity of CDK2 for both histone substrate and ATP and decreases its affinity
for ADP. By contrast, phosphorylation of CDK2 has a negligible effect on the
affinity for cyclin A. The crystal structures of the ATP-bound forms of
phosphorylated CDK2 and unphosphorylated CDK2 have been solved at 2.1-A
resolution. The structures are similar, with the major difference occurring in
the activation segment, which is disordered in phosphorylated CDK2. The greater
mobility of the activation segment in phosphorylated CDK2 and the absence of
spontaneous crystallization suggest that phosphorylated CDK2 may adopt several
different mobile states. The majority of these states are likely to correspond
to inactive conformations, but a small fraction of phosphorylated CDK2 may be in
an active conformation and hence explain the basal activity observed.
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Figure 2.
Fig. 2. CDK-associated phosphatase KAP dephosphorylates
phosphorylated CDK2. KAP specifically dephosphorylates monomeric
phosphorylated CDK2.
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Figure 6.
Fig. 6. a, the fold of monomeric CDK2. The structure is
shown in a schematic representation with regions of  -sheet shown
as arrows and  -helix
shown as ribbons. The N-terminal domain is colored principally
white, with the exception of the glycine-rich loop (colored
magenta), and the C-helix (PSTAIRE helix, colored gold). The
region of the N-terminal domain for which no trace is visible
(residues 36-43) is indicated by small black spheres identifying
residues 35 and 44. ATP is shown in ball and stick
representation at the interface between the N- and C-terminal
domains. The C-terminal domain is colored pink, with the
activation segment (residues 145-172) highlighted in cyan. b,
comparison of electron density for the tip of the activation
segment. The upper stereo pair shows electron density defining
the conformation of residues at the tip of the activation
segment (residues 155-165) in the ATP complex of
unphosphorylated monomeric CDK2, while the lower stereo pair
shows the equivalent electron density in phosphorylated
monomeric CDK2. In this figure the phosphate group attached to
Thr^160 has been omitted from the phosphorylated CDK2 structure
for clarity. The maps were calculated using (2F[o]  F[c]) [calc]
coefficients generated by REFMAC and are contoured at a level of
0.2e^  Å^
3. c,
B-factor plots for CDK2-ATP and phosphorylated CDK2-ATP. The
mean main chain B-factor of each residue along the polypeptide
chain is shown for unphosphorylated CDK2 (thin lines) and
phosphorylated CDK2 (thick lines). The outstanding regions of
difference include the glycine loop (residues 8-18) and the tip
of the activation segment (residues 155-165). d, detail of the
fold of the CDK2-ATP complex. The interaction of Tyr^159 and
Thr^160, at the tip of the activation segment, with residues
Glu^12-Tyr^15 in the glycine-rich loop is shown. The coloring
scheme is the same as for a.
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The above figures are
reprinted
by permission from the ASBMB:
J Biol Chem
(1999,
274,
8746-8756)
copyright 1999.
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Secondary reference #1
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Title
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Multiple modes of ligand recognition: crystal structures of cyclin-Dependent protein kinase 2 in complex with ATP and two inhibitors, Olomoucine and isopentenyladenine.
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Authors
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U.Schulze-Gahmen,
J.Brandsen,
H.D.Jones,
D.O.Morgan,
L.Meijer,
J.Vesely,
S.H.Kim.
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Ref.
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Proteins, 1995,
22,
378-391.
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PubMed id
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