Catalysis of the reaction: 2 GTP = cyclic di-3',5'-guanylate + 2 diphosphate + 2 H(+).

Catalysis of the reaction: 2 GTP = cyclic di-3',5'-guanylate + 2 diphosphate + 2 H(+).

Interacting selectively and non-covalently with any protein or protein complex (a complex of two or more proteins that may include other nonprotein molecules).

Interacting selectively and non-covalently with oxygen (O2).

Interacting selectively and non-covalently with heme, any compound of iron complexed in a porphyrin (tetrapyrrole) ring.

Interacting selectively and non-covalently with carbon monoxide (CO).

Interacting selectively and non-covalently with an identical protein or proteins.

Catalysis of the phosphorylation of a histidine residue in response to detection of an extracellular signal such as a chemical ligand or change in environment, to initiate a change in cell state or activity. The two-component sensor is a histidine kinase that autophosphorylates a histidine residue in its active site. The phosphate is then transferred to an aspartate residue in a downstream response regulator, to trigger a response.

The function of absorbing and responding to electromagnetic radiation with a wavelength of approximately 660-730nm. The response may involve a change in conformation.

Catalysis of a biochemical reaction at physiological temperatures. In biologically catalyzed reactions, the reactants are known as substrates, and the catalysts are naturally occurring macromolecular substances known as enzymes. Enzymes possess specific binding sites for substrates, and are usually composed wholly or largely of protein, but RNA that has catalytic activity (ribozyme) is often also regarded as enzymatic.

Catalysis of the reaction: GTP = 3',5'-cyclic GMP + diphosphate.

Interacting selectively and non-covalently with any protein or protein complex (a complex of two or more proteins that may include other nonprotein molecules).