View source for 6z44


==Crystal structure of the cAMP-dependent protein kinase A in complex with phenol==
<StructureSection load='6z44' size='340' side='right'caption='[[6z44]], [[Resolution|resolution]] 1.38&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6z44]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Cho_cell_lines Cho cell lines]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6Z44 OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=6Z44 FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=DMS:DIMETHYL+SULFOXIDE'>DMS</scene>, <scene name='pdbligand=IPH:PHENOL'>IPH</scene>, <scene name='pdbligand=MRD:(4R)-2-METHYLPENTANE-2,4-DIOL'>MRD</scene></td></tr>
<tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=SEP:PHOSPHOSERINE'>SEP</scene>, <scene name='pdbligand=TPO:PHOSPHOTHREONINE'>TPO</scene></td></tr>
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">PRKACA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=10029 CHO cell lines])</td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/cAMP-dependent_protein_kinase cAMP-dependent protein kinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.11.11 2.7.11.11] </span></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=6z44 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6z44 OCA], [http://pdbe.org/6z44 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6z44 RCSB], [http://www.ebi.ac.uk/pdbsum/6z44 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6z44 ProSAT]</span></td></tr>
</table>
== Function ==
[[http://www.uniprot.org/uniprot/KAPCA_CRIGR KAPCA_CRIGR]] Phosphorylates a large number of substrates in the cytoplasm and the nucleus. Regulates the abundance of compartmentalized pools of its regulatory subunits through phosphorylation of PJA2 which binds and ubiquitinates these subunits, leading to their subsequent proteolysis. Phosphorylates CDC25B, ABL1, NFKB1, CLDN3, PSMC5/RPT6, PJA2, RYR2, RORA and VASP. RORA is activated by phosphorylation. Required for glucose-mediated adipogenic differentiation increase and osteogenic differentiation inhibition from osteoblasts. Involved in the regulation of platelets in response to thrombin and collagen; maintains circulating platelets in a resting state by phosphorylating proteins in numerous platelet inhibitory pathways when in complex with NF-kappa-B (NFKB1 and NFKB2) and I-kappa-B-alpha (NFKBIA), but thrombin and collagen disrupt these complexes and free active PRKACA stimulates platelets and leads to platelet aggregation by phosphorylating VASP. Prevents the antiproliferative and anti-invasive effects of alpha-difluoromethylornithine in breast cancer cells when activated. RYR2 channel activity is potentiated by phosphorylation in presence of luminal Ca(2+), leading to reduced amplitude and increased frequency of store overload-induced Ca(2+) release (SOICR) characterized by an increased rate of Ca(2+) release and propagation velocity of spontaneous Ca(2+) waves, despite reduced wave amplitude and resting cytosolic Ca(2+). PSMC5/RPT6 activation by phosphorylation stimulates proteasome. Negatively regulates tight junctions (TJs) in ovarian cancer cells via CLDN3 phosphorylation. NFKB1 phosphorylation promotes NF-kappa-B p50-p50 DNA binding. Involved in embryonic development by down-regulating the Hedgehog (Hh) signaling pathway that determines embryo pattern formation and morphogenesis. Prevents meiosis resumption in prophase-arrested oocytes via CDC25B inactivation by phosphorylation. May also regulate rapid eye movement (REM) sleep in the pedunculopontine tegmental (PPT) (By similarity). Phosphorylates APOBEC3G and AICDA (By similarity). 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Medicinal-chemistry optimization follows strategies replacing functional groups and attaching larger substituents at a promising lead scaffold. Well-established bioisosterism rules are considered, however, it is difficult to estimate whether the introduced modifications really match the required properties at a binding site. The electron density distribution and pKa values are modulated influencing protonation states and bioavailability. Considering the adjacent H-bond donor/acceptor pattern of the hinge binding motif in a kinase, we studied by crystallography a set of fragments to map the required interaction pattern. Unexpectedly, benzoic acid and benzamidine, decorated with the correct substituents, are totally bioisosteric just as carboxamide and phenolic OH. A mono-dentate pyridine nitrogen out-performs bi-dentate functionalities. The importance of correctly designing pKa values of attached functional groups by additional substituents at the parent scaffold is rendered prominent.

Fragment Binding to Kinase Hinge: If Charge Distribution and Local pKa Shifts Mislead Popular Bioisosterism Concepts.,Oebbeke M, Siefker C, Wagner B, Heine A, Klebe G Angew Chem Int Ed Engl. 2020 Oct 6. doi: 10.1002/anie.202011295. PMID:33021032<ref>PMID:33021032</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6z44" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Cho cell lines]]
[[Category: Large Structures]]
[[Category: CAMP-dependent protein kinase]]
[[Category: Heine, A]]
[[Category: Klebe, G]]
[[Category: Oebbeke, M]]
[[Category: Glycogen metabolism]]
[[Category: Phosphotransferase]]
[[Category: Serine/threonine kinase]]
[[Category: Signalling pathway]]
[[Category: Transferase]]