This domain is found towards the C-terminal the U3 small nucleolar RNA-associated protein 20 (UTP20) from yeast and its human homologue, also known as DRIM (Down-Regulated In Metastasis). DRIM is differentially expressed in metastatic and non-metastatic human breast carcinoma cells [1]. Proteins of this entry are involved in processing of non-coding RNA as components of the small-subunit (SSU) processome; SSU processome is involved in the biogenesis of the 18S rRNA [2,3]. UTP20 is a huge alpha-solenoid that functions as a scaffold [4,5].

1: Differential gene expression in mammary carcinoma cell lines: identification of DRIM, a new gene down-regulated in metastasis. Schwirzke M, Gnirke A, Bork P, Tarin D, Weidle UH; Anticancer Res 1998;18:1409-1421. PMID:9673349

2: A panoramic view of yeast noncoding RNA processing. Peng WT, Robinson MD, Mnaimneh S, Krogan NJ, Cagney G, Morris Q, Davierwala AP, Grigull J, Yang X, Zhang W, Mitsakakis N, Ryan OW, Datta N, Jojic V, Pal C, Canadien V, Richards D, Beattie B, Wu LF, Altschuler SJ, Roweis S, Frey BJ, Emili A, Greenblatt JF, Cell 2003;113:919-933. PMID:12837249

3: Human 1A6/DRIM, the homolog of yeast Utp20, functions in the 18S rRNA processing. Wang Y, Liu J, Zhao H, Lu W, Zhao J, Yang L, Li N, Du X, Ke Y; Biochim Biophys Acta. 2007;1773:863-868. PMID:17498821

4: Thermophile 90S Pre-ribosome Structures Reveal the Reverse Order of Co-transcriptional 18S rRNA Subdomain Integration. Cheng J, Bassler J, Fischer P, Lau B, Kellner N, Kunze R, Griesel S, Kallas M, Berninghausen O, Strauss D, Beckmann R, Hurt E; Mol Cell. 2019;75:1256-1269. PMID:31378463

5: Cryo-EM structure of 90S small ribosomal subunit precursors in transition states. Du Y, An W, Zhu X, Sun Q, Qi J, Ye K; Science. 2020;369:1477-1481. PMID:32943522