Homologous Superfamily

GAF-like domain superfamily (IPR029016)

Short name: GAF-like_dom_sf

Overlapping entries


This superfamily represents the GAF domain and domains sharing protein structural similarity, such as the C-terminal domain of the transcription regulator IclR, the C-terminal domain of the heat-inducible transcription repressor HrcA, and the phytochrome chromophore attachment domain.

The GAF domain is named after some of the proteins it is found in, including cGMP-specific phosphodiesterases, adenylyl cyclases and FhlA. It is also found in guanylyl cyclases and phytochromes [PMID: 9433123, PMID: 20004158]. The structure of a GAF domain shows that the domain shares a similar fold with the PAS domain [PMID: 11032796]. Adenylyl and guanylyl cyclases catalyse ATP and GTP to the second messengers cAMP and cGMP respectively; these products up-regulate catalytic activity by binding to the regulatory GAF domain(s). The opposite hydrolysis reaction is catalysed by phosphodiesterase. cGMP-dependent 3',5'-cyclic phosphodiesterase catalyses the conversion of guanosine 3',5'-cyclic phosphate to guanosine 5'-phosphate. Here too, cGMP regulates catalytic activity by GAF-domain binding.

Phytochromes are regulatory photoreceptors in plants and bacteria which exist in two thermally stable states that are reversibly inter-convertible by light, the Pr state absorbs maximally in the red region of the spectrum, while the Pfr state absorbs maximally in the far-red region [PMID: 20298248].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.