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==CONTROL OF PHOSPHORYLASE B CONFORMATION BY A MODIFIED COFACTOR: CRYSTALLOGRAPHIC STUDIES ON R-STATE GLYCOGEN PHOSPHORYLASE RECONSTITUTED WITH PYRIDOXAL 5'-DIPHOSPHATE== | |||
<StructureSection load='1abb' size='340' side='right'caption='[[1abb]], [[Resolution|resolution]] 2.80Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1abb]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Oryctolagus_cuniculus Oryctolagus cuniculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ABB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1ABB FirstGlance]. <br> | |||
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.8Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=IMP:INOSINIC+ACID'>IMP</scene>, <scene name='pdbligand=PDP:PYRIDOXAL-5-DIPHOSPHATE'>PDP</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr> | |||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1abb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1abb OCA], [https://pdbe.org/1abb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1abb RCSB], [https://www.ebi.ac.uk/pdbsum/1abb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1abb ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/PYGM_RABIT PYGM_RABIT] Phosphorylase is an important allosteric enzyme in carbohydrate metabolism. Enzymes from different sources differ in their regulatory mechanisms and in their natural substrates. However, all known phosphorylases share catalytic and structural properties. | |||
== Evolutionary Conservation == | |||
[[Image:Consurf_key_small.gif|200px|right]] | |||
Check<jmol> | |||
<jmolCheckbox> | |||
<scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ab/1abb_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked> | |||
<text>to colour the structure by Evolutionary Conservation</text> | |||
</jmolCheckbox> | |||
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1abb ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Previous crystallographic studies on glycogen phosphorylase have described the different conformational states of the protein (T and R) that represent the allosteric transition and have shown how the properties of the 5'-phosphate group of the cofactor pyridoxal phosphate are influenced by these conformational states. The present work reports a study on glycogen phosphorylase b (GPb) complexed with a modified cofactor, pyridoxal 5'-diphosphate (PLPP), in place of the natural cofactor. Solution studies (Withers, S.G., Madsen, N.B., & Sykes, B.D., 1982, Biochemistry 21, 6716-6722) have shown that PLPP promotes R-state properties of the enzyme indicating that the cofactor can influence the conformational state of the protein. GPb complexed with pyridoxal 5'-diphosphate (PLPP) has been crystallized in the presence of IMP and ammonium sulfate in the monoclinic R-state crystal form and the structure refined from X-ray data to 2.8 A resolution to a crystallographic R value of 0.21. The global tertiary and quaternary structure in the vicinity of the Ser 14 and the IMP sites are nearly identical to those observed for the R-state GPb-AMP complex. At the catalytic site the second phosphate of PLPP is accommodated with essentially no change in structure from the R-state structure and is involved in interactions with the side chains of two lysine residues (Lys 568 and Lys 574) and the main chain nitrogen of Arg 569. Superposition of the T-state structure shows that were the PLPP to be incorporated into the T-state structure there would be a close contact with the 280s loop (residues 282-285) that would encourage the T to R allosteric transition. The second phosphate of the PLPP occupies a site that is distinct from other dianionic binding sites that have been observed for glucose-1-phosphate and sulfate (in the R state) and for heptulose-2-phosphate (in the T state). The results indicate mobility in the dianion recognition site, and the precise position is dependent on other linkages to the dianion. In the modified cofactor the second phosphate site is constrained by the covalent link to the first phosphate of PLPP. The observed position in the crystal suggests that it is too far from the substrate site to represent a site for catalysis. | |||
Control of phosphorylase b conformation by a modified cofactor: crystallographic studies on R-state glycogen phosphorylase reconstituted with pyridoxal 5'-diphosphate.,Leonidas DD, Oikonomakos NG, Papageorgiou AC, Acharya KR, Barford D, Johnson LN Protein Sci. 1992 Sep;1(9):1112-22. PMID:1304390<ref>PMID:1304390</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 1abb" style="background-color:#fffaf0;"></div> | |||
== | ==See Also== | ||
*[[Glycogen phosphorylase 3D structures|Glycogen phosphorylase 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Large Structures]] | |||
[[Category: Oryctolagus cuniculus]] | [[Category: Oryctolagus cuniculus]] | ||
[[Category: Acharya KR]] | |||
[[Category: Barford D]] | |||
[[Category: Acharya | [[Category: Johnson LN]] | ||
[[Category: Barford | [[Category: Leonidas DD]] | ||
[[Category: Johnson | [[Category: Oikonomakos NG]] | ||
[[Category: Leonidas | [[Category: Papageorgiou AC]] | ||
[[Category: Oikonomakos | |||
[[Category: Papageorgiou | |||