4g86

From Proteopedia

(Difference between revisions)

Revision as of 23:43, 24 December 2014

Crystal structure of the redox-active cofactor DBMIB bound to the full length circadian clock protein KaiA from Synechococcus elongatus

Structural highlights

4g86 is a 2 chain structure with sequence from Synechococcus elongatus pcc 7942. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:	, , ,
Related:	1r8j
Gene:	kaiA, see0009, Synpcc7942_1218 (Synechococcus elongatus PCC 7942)
Resources:	FirstGlance, OCA, RCSB, PDBsum

Function

[KAIA_SYNE7] Component of the KaiABC clock protein complex, which constitutes the main circadian regulator in cyanobacteria. The KaiABC complex may act as a promoter-nonspecific transcription regulator that represses transcription, possibly by acting on the state of chromosome compaction. In the complex, it enhances the phosphorylation status of KaiC. In contrast, the presence of KaiB in the complex decreases the phosphorylation status of KaiC, suggesting that KaiB acts by antagonizing the interaction between KaiA and KaiC. A KaiA dimer is sufficient to enhance KaiC hexamer phosphorylation.^[1] ^[2] ^[3] ^[4]

Publication Abstract from PubMed

KaiA protein that stimulates KaiC phosphorylation in the cyanobacterial circadian clock was recently shown to be destabilized by dibromothymoquinone (DBMIB), thus revealing KaiA as a sensor of the plastoquinone (PQ) redox state and suggesting an indirect control of the clock by light through PQ redox changes. Here we show using X-ray crystallography that several DBMIBs are bound to KaiA dimer. Some binding modes are consistent with oligomerization of N-terminal KaiA pseudoreceiver domains and/or reduced interdomain flexibility. DBMIB bound to the C-terminal KaiA (C-KaiA) domain and limited stimulation of KaiC kinase activity by C-KaiA in the presence of DBMIB demonstrate that the cofactor may weakly inhibit KaiA-KaiC binding.

Crystal Structure of the Redox-Active Cofactor Dibromothymoquinone Bound to Circadian Clock Protein KaiA and Structural Basis for Dibromothymoquinone's Ability to Prevent Stimulation of KaiC Phosphorylation by KaiA.,Pattanayek R, Sidiqi SK, Egli M Biochemistry. 2012 Oct 5. PMID:23020633^[5]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Iwasaki H, Nishiwaki T, Kitayama Y, Nakajima M, Kondo T. KaiA-stimulated KaiC phosphorylation in circadian timing loops in cyanobacteria. Proc Natl Acad Sci U S A. 2002 Nov 26;99(24):15788-93. Epub 2002 Oct 21. PMID:12391300 doi:http://dx.doi.org/10.1073/pnas.222467299
↑ Xu Y, Mori T, Johnson CH. Cyanobacterial circadian clockwork: roles of KaiA, KaiB and the kaiBC promoter in regulating KaiC. EMBO J. 2003 May 1;22(9):2117-26. PMID:12727878 doi:10.1093/emboj/cdg168
↑ Kitayama Y, Iwasaki H, Nishiwaki T, Kondo T. KaiB functions as an attenuator of KaiC phosphorylation in the cyanobacterial circadian clock system. EMBO J. 2003 May 1;22(9):2127-34. PMID:12727879 doi:10.1093/emboj/cdg212
↑ Ishiura M, Kutsuna S, Aoki S, Iwasaki H, Andersson CR, Tanabe A, Golden SS, Johnson CH, Kondo T. Expression of a gene cluster kaiABC as a circadian feedback process in cyanobacteria. Science. 1998 Sep 4;281(5382):1519-23. PMID:9727980
↑ Pattanayek R, Sidiqi SK, Egli M. Crystal Structure of the Redox-Active Cofactor Dibromothymoquinone Bound to Circadian Clock Protein KaiA and Structural Basis for Dibromothymoquinone's Ability to Prevent Stimulation of KaiC Phosphorylation by KaiA. Biochemistry. 2012 Oct 5. PMID:23020633 doi:http://dx.doi.org/10.1021/bi301222t

1 Structural highlights
2 Function
3 Publication Abstract from PubMed
4 See Also
5 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/4g86"

@@ Line 8: / Line 8: @@
 <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4g86 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4g86 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4g86 RCSB], [http://www.ebi.ac.uk/pdbsum/4g86 PDBsum]</span></td></tr>
 </table>
+== Function ==
+[[http://www.uniprot.org/uniprot/KAIA_SYNE7 KAIA_SYNE7]] Component of the KaiABC clock protein complex, which constitutes the main circadian regulator in cyanobacteria. The KaiABC complex may act as a promoter-nonspecific transcription regulator that represses transcription, possibly by acting on the state of chromosome compaction. In the complex, it enhances the phosphorylation status of KaiC. In contrast, the presence of KaiB in the complex decreases the phosphorylation status of KaiC, suggesting that KaiB acts by antagonizing the interaction between KaiA and KaiC. A KaiA dimer is sufficient to enhance KaiC hexamer phosphorylation.<ref>PMID:12391300</ref> <ref>PMID:12727878</ref> <ref>PMID:12727879</ref> <ref>PMID:9727980</ref>
 <div style="background-color:#fffaf0;">
 == Publication Abstract from PubMed ==

4g86

From Proteopedia

Revision as of 23:43, 24 December 2014

Crystal structure of the redox-active cofactor DBMIB bound to the full length circadian clock protein KaiA from Synechococcus elongatus

Structural highlights

Function

Publication Abstract from PubMed

See Also

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

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