Proposed model of the heterodimeric sGC enzyme complex based on the results of FRET analysis and fusion of sGC subunits.

The dimensions of the domains are given on the basis of the crystal structures of domain homologues (H-NOX, PDB ID 2O09 [9]; PAS, PDB ID 2P04 [13]; cat PDB ID 3ET6 [5]) and the structure of the coiled coil domain of the β₁ subunit (PDB ID 3HLS [18]). Elongated model of the sGC (A). Model according to our results (B). Model of fluorescent-conjoined sGC (C). The β₁ subunit is shown in red and the α subunit is shown in blue. cat - catalytic domain, CC - coiled coil region, PAS - Per-Arnt-Sim fold, HNOX - heme nitric oxide/oxygen binding domain.