6AO9:
reference: Structure and monomer/dimer equilibrium for the guanylyl cyclase domain of the optogenetics protein RhoGC., Kumar RP, Morehouse BR, Fofana J, Trieu MM, Zhou DH, Lorenz MO, Oprian DD, J Biol Chem. 2017 Nov 8. pii: jbc.M117.812685. doi: 10.1074/jbc.M117.812685. PMID: 29118188

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