InterPro domain: IPR006936

The 125-residue ALOG (Arabidopsis LSH1 and oryza G1) domain is rich in basicamino acids, especially arginine, and is highly conserved among land plants.Members of the ALOG family of proteins function as key developmentalregulators. It has been proposed that the ALOG domain originated from the N-terminal DNA-binding domains of integrases belonging to the tyrosinerecombinase superfamily encoded by a distinct type of DIRS1-like LTRretrotransposon found in several eukaryotes. Secondary structure predictionsrevealed an all-alpha helical domain with four conserved helices [ 1 , 2 ].

Some proteins known to contain an ALOG domain are listed below:

• Arabidopsis thaliana LIGHT_DEPENDENT SHORT HYPOCOTYLS1 (LSH1), involved in phytochrome-dependent light signalling.
• Oryza G1, involved in the specification of sterile lemma identity.
• Plant defence proteins.

1. The homeotic gene long sterile lemma (G1) specifies sterile lemma identity in the rice spikelet. Proc. Natl. Acad. Sci. U.S.A. 106, 20103-8
2. ALOG domains: provenance of plant homeotic and developmental regulators from the DNA-binding domain of a novel class of DIRS1-type retroposons. Biol. Direct 7, 39