This domain is found in the conserved fungal proteins SPP41 (suppressor of PrP4, there are four members, 1 to 4). In S. cerevisiae it is conserved towards the C-terminus of HMG domains. The function is not known. However, it has been shown that SPP41 is involved in negative regulation of expression of spliceosome components PRP4 and PRP3 and that it relocalizes to the cytosol in response to hypoxia [1,2].

1: Extragenic suppressors of Saccharomyces cerevisiae prp4 mutations identify a negative regulator of PRP genes. Maddock JR, Weidenhammer EM, Adams CC, Lunz RL, Woolford JL Jr; Genetics. 1994;136:833-847. PMID:8005438

2: The nuclear localization of SWI/SNF proteins is subjected to oxygen regulation. Dastidar RG, Hooda J, Shah A, Cao TM, Henke RM, Zhang L; Cell Biosci. 2012;2:30. PMID:22932476