1WC6

Soluble adenylyl cyclase CyaC from S. platensis in complex with Rp- ATPalphaS in presence of bicarbonate


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.51 Å
  • R-Value Free: 0.291 
  • R-Value Work: 0.241 
  • R-Value Observed: 0.241 

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This is version 1.2 of the entry. See complete history


Literature

Bicarbonate Activation of Adenylyl Cyclase Via Promotion of Catalytic Active Site Closure and Metal Recruitment

Steegborn, C.Litvin, T.N.Levin, L.R.Buck, J.Wu, H.

(2005) Nat Struct Mol Biol 12: 32

  • DOI: 10.1038/nsmb880
  • Primary Citation of Related Structures:  
    1WC4, 1WC3, 1WC1, 1WC0, 1WC6, 1WC5

  • PubMed Abstract: 
  • In an evolutionarily conserved signaling pathway, 'soluble' adenylyl cyclases (sACs) synthesize the ubiquitous second messenger cyclic adenosine 3',5'-monophosphate (cAMP) in response to bicarbonate and calcium signals. Here, we present crystal structures of a cyanobacterial sAC enzyme in complex with ATP analogs, calcium and bicarbonate, which represent distinct catalytic states of the enzyme ...

    In an evolutionarily conserved signaling pathway, 'soluble' adenylyl cyclases (sACs) synthesize the ubiquitous second messenger cyclic adenosine 3',5'-monophosphate (cAMP) in response to bicarbonate and calcium signals. Here, we present crystal structures of a cyanobacterial sAC enzyme in complex with ATP analogs, calcium and bicarbonate, which represent distinct catalytic states of the enzyme. The structures reveal that calcium occupies the first ion-binding site and directly mediates nucleotide binding. The single ion-occupied, nucleotide-bound state defines a novel, open adenylyl cyclase state. In contrast, bicarbonate increases the catalytic rate by inducing marked active site closure and recruiting a second, catalytic ion. The phosphates of the bound substrate analogs are rearranged, which would facilitate product formation and release. The mechanisms of calcium and bicarbonate sensing define a reaction pathway involving active site closure and metal recruitment that may be universal for class III cyclases.


    Organizational Affiliation

    Department of Biochemistry, Weill Medical College of Cornell University, 1300 York Avenue, New York, New York 10021, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
ADENYLATE CYCLASEA, B, C226Arthrospira platensisMutation(s): 0 
Gene Names: cyaC
EC: 4.6.1.1
UniProt
Find proteins for O32393 (Arthrospira platensis)
Explore O32393 
Go to UniProtKB:  O32393
Protein Feature View
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  • Reference Sequence
Small Molecules
Binding Affinity Annotations 
IDSourceBinding Affinity
TAT PDBBind:  1WC6 Ki: 1.00e+5 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.51 Å
  • R-Value Free: 0.291 
  • R-Value Work: 0.241 
  • R-Value Observed: 0.241 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 51.148α = 90
b = 73.965β = 90
c = 266.861γ = 90
Software Package:
Software NamePurpose
CNSrefinement
DENZOdata reduction
SCALEPACKdata scaling
MOLREPphasing

Structure Validation

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Ligand Structure Quality Assessment  



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2004-12-20
    Type: Initial release
  • Version 1.1: 2013-02-06
    Changes: Atomic model, Derived calculations, Other, Refinement description, Version format compliance
  • Version 1.2: 2014-02-05
    Changes: Atomic model, Other