1M2F | pdb_00001m2f

Solution structure of the N-terminal domain of Synechococcus elongatus KaiA (KaiA135N); Family of 25 structures

• PDB DOI: https://doi.org/10.2210/pdb1M2F/pdb
• BMRB: 5031

• Classification: CIRCADIAN CLOCK PROTEIN
• Organism(s): Synechococcus elongatus
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): No 


• Deposited: 2002-06-23 Released: 2002-11-13 
• Deposition Author(s): Williams, S.B., Vakonakis, I., Golden, S.S., LiWang, A.C.

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Experimental Data Snapshot

• Method: SOLUTION NMR
• Conformers Calculated: 50 
• Conformers Submitted: 25 
• Selection Criteria: structures with the lowest energy 

Literature

Structure and Function from the Circadian Clock Protein KaiA of Synechococcus elongatus: A potential Clock Input Mechanism

Williams, S.B., Vakonakis, I., Golden, S.S., LiWang, A.C.

(2002) Proc Natl Acad Sci U S A 99: 15357-15362

• PubMed: 12438647 
• DOI: https://doi.org/10.1073/pnas.232517099
• Primary Citation Related Structures: 
  1M2E, 1M2F


• PubMed Abstract: 
  

  In the cyanobacterium Synechococcus elongatus (PCC 7942) the proteins KaiA, KaiB, and KaiC are required for circadian clock function. We deduced a circadian clock function for KaiA from a combination of biochemical and structural data. Both KaiA and its isolated carboxyl-terminal domain (KaiA180C) stimulated KaiC autophosphorylation and facilitated attenuation of KaiC autophosphorylation by KaiB. An amino-terminal domain (KaiA135N) had no function in the autophosphorylation assay. NMR structure determination showed that KaiA135N is a pseudo-receiver domain. We propose that this pseudo-receiver is a timing input-device that regulates KaiA stimulation of KaiC autophosphorylation, which in turn is essential for circadian timekeeping.

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Organizational Affiliation: 
• Department of Biology, Texas A&M University, College Station 77843, USA.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Macromolecule Content 

• Total Structure Weight: 15.08 kDa 
• Atom Count: 1,055 
• Modeled Residue Count: 135 
• Deposited Residue Count: 135 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
KaiA	A	135	Synechococcus elongatus	Mutation(s): 0  Gene Names: KaiA
UniProt
Find proteins for Q79PF6 (Synechococcus elongatus (strain ATCC 33912 / PCC 7942 / FACHB-805)) Explore Q79PF6  Go to UniProtKB:  Q79PF6

Experimental Data & Validation

Experimental Data

• Method: SOLUTION NMR
• Conformers Calculated: 50 
• Conformers Submitted: 25 
• Selection Criteria: structures with the lowest energy 

Structure Validation

Entry History 

Deposition Data

• Released Date: 2002-11-13 
Deposition Author(s): Williams, S.B., Vakonakis, I., Golden, S.S., LiWang, A.C.

Revision History  

• Version 1.0: 2002-11-13
  Type: Initial release
  
• Version 1.1: 2008-04-28
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2022-02-23
  Changes: Database references, Derived calculations
• Version 1.4: 2024-05-22
  Changes: Data collection