2W01

Crystal structure of the guanylyl cyclase Cya2


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.31 Å
  • R-Value Free: 0.282 
  • R-Value Work: 0.194 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Crystal Structure of the Guanylyl Cyclase Cya2.

Rauch, A.Leipelt, M.Russwurm, M.Steegborn, C.

(2008) Proc.Natl.Acad.Sci.USA 105: 15720

  • DOI: 10.1073/pnas.0808473105

  • PubMed Abstract: 
  • Cyclic GMP (cGMP) is an important second messenger in eukaryotes. It is formed by guanylyl cyclases (GCs), members of the nucleotidyl cyclases class III, which also comprises adenylyl cyclases (ACs) from most organisms. To date, no structures of euka ...

    Cyclic GMP (cGMP) is an important second messenger in eukaryotes. It is formed by guanylyl cyclases (GCs), members of the nucleotidyl cyclases class III, which also comprises adenylyl cyclases (ACs) from most organisms. To date, no structures of eukaryotic GCs are available, and all bacterial class III proteins were found to be ACs. Here we describe the biochemical and structural characterization of the class III cyclase Cya2 from cyanobacterium Synechocystis PCC6803. Cya2 shows high specificity for GTP versus ATP, revealing it to be the first bacterial GC, and sequence similarity searches indicate that GCs are also present in other bacteria. The crystal structure of Cya2 provides first structural insights into the universal GC family. Structure and mutagenesis studies show that a conserved glutamate, assisted by an interacting lysine, dominates substrate selection by forming hydrogen bonds to the substrate base. We find, however, that a second residue involved in substrate selection has an unexpected sterical role in GCs, different from its hydrogen bonding function in the related ACs. The structure identifies a tyrosine that lines the guanine binding pocket as additional residue contributing to substrate specificity. Furthermore, we find that substrate specificity stems from faster turnover of GTP, rather than different affinities for GTP and ATP, implying that the specificity-determining interactions are established after the binding step.


    Organizational Affiliation

    Department of Physiological Chemistry, Ruhr-University Bochum, Universitaetsstrasse 150, 44801 Bochum, Germany.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
ADENYLATE CYCLASE
A, B, C, D, E, F
208Synechocystis sp. (strain PCC 6803 / Kazusa)Mutation(s): 0 
Gene Names: cyaA
Find proteins for P72951 (Synechocystis sp. (strain PCC 6803 / Kazusa))
Go to UniProtKB:  P72951
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.31 Å
  • R-Value Free: 0.282 
  • R-Value Work: 0.194 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 62.445α = 90.00
b = 84.090β = 97.40
c = 115.328γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data scaling
HKL-2000data reduction
PHASERphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2008-09-30
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Advisory, Version format compliance