This domain is part of an RNase-H fold section in a number of hAT-like transposases, such as protein DAYSLEEPER (At3g42170) from Arabidopsis [1]. Protein DAYSLEEPER is essential for plant development and can also regulate global gene expression [2]. This entry also includes some uncharacterised fungal proteins.

1: DAYSLEEPER: a nuclear and vesicular-localized protein that is expressed in proliferating tissues. Knip M, Hiemstra S, Sietsma A, Castelein M, de Pater S, Hooykaas P; BMC Plant Biol. 2013;13:211. PMID:24330683

2: An Arabidopsis hAT-like transposase is essential for plant development. Bundock P, Hooykaas P; Nature. 2005;436:282-284. PMID:16015335