This domain of unknown function is found in Focadhesin from animals and RST1 (RESURRECTION 1) from plants. Focadhesin (FOCAD) is a focal adhesion protein with potential tumour suppressor function in gliomas [1]. RST1 was originally identified in a genetic screen for factors involved in the biosynthesis of epicuticular waxes [2]. Later, RST1 and RST1 INTERACTING PROTEIN (RIPR) have been shown to act as cofactors of the cytoplasmic exosome and the Ski complex in plants [3]. It is involved in the suppression of siRNA-mediated silencing of transgenes and certain endogenous transcripts [4]. Structure predictions suggest that this is an alpha-helical domain with and armadillo-like fold.

1: KIAA1797/FOCAD encodes a novel focal adhesion protein with tumour suppressor function in gliomas. Brockschmidt A, Trost D, Peterziel H, Zimmermann K, Ehrler M, Grassmann H, Pfenning PN, Waha A, Wohlleber D, Brockschmidt FF, Jugold M, Hoischen A, Kalla C, Waha A, Seifert G, Knolle PA, Latz E, Hans VH, Wick W, Pfeifer A, Angel P, Weber RG; Brain. 2012;135:1027-1041. PMID:22427331

2: Mutation of the RESURRECTION1 locus of Arabidopsis reveals an association of cuticular wax with embryo development. Chen X, Goodwin SM, Liu X, Chen X, Bressan RA, Jenks MA; Plant Physiol. 2005;139:909-919. PMID:16183838

3: RST1 and RIPR connect the cytosolic RNA exosome to the Ski complex in Arabidopsis. Lange H, Ndecky SYA, Gomez-Diaz C, Pflieger D, Butel N, Zumsteg J, Kuhn L, Piermaria C, Chicher J, Christie M, Karaaslan ES, Lang PLM, Weigel D, Vaucheret H, Hammann P, Gagliardi D; Nat Commun. 2019;10:3871. PMID:31455787

4: A genetics screen highlights emerging roles for CPL3, RST1 and URT1 in RNA metabolism and silencing. Li T, Natran A, Chen Y, Vercruysse J, Wang K, Gonzalez N, Dubois M, Inze D; Nat Plants. 2019;5:539-550. PMID:31076735