2w01

Crystal structure of the guanylyl cyclase Cya2

spinqualitylabelsall models 2w01, resolution 2.31Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2w01 is a 6 chain structure with sequence from Synechocystis sp. PCC 6803. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.31Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function P72951_SYNY3 Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed 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. Crystal structure of the guanylyl cyclase Cya2.,Rauch A, Leipelt M, Russwurm M, Steegborn C Proc Natl Acad Sci U S A. 2008 Oct 14;105(41):15720-5. Epub 2008 Oct 7. PMID:18840690 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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