Fig. 2.

Alignment of candidate cyclic nucleotide binding proteins with known GAF domains. Representative GAF domains (IPR003018) include those from human (Hs) phosphodiesterases PDE2, PDE5; Anabaena sp. PCC 7120 (An) adenylyl cyclases CYAB1, CYAB2, CYAC1, CYAC2; and E. coli (Ec) FhlA. Where the protein has tandem GAF domains these are indicated by the letters “a” and “b”. The number in parenthesis indicates the number of amino acids that have been omitted. The * indicates conserved amino acids across species. The cysteine residues that have been circled are sites of S-nitrosylation. The Arabidopsis CNBP candidates EIF4A1, PGK1, GAPB, TKL, SHMT1, GOX1 and CA1 align with the GAF domain. The site of S-nitrosylation in the CNBP candidate CA1 is found within the GAF domain although it is distant from the S-nitrosylation site in human PDE5.