This is the AlbA_2 domain from the Schlafen (SLFN) family of proteins which are important in cell differentiation and defense against viruses [1,2]. This domain is present at the N-terminal of all SLFN proteins and includes the SLFN box, a sequence unique to these proteins that may form a dimer interface [1]. The AlbA_2 domain is RNA-binding and RNase region as it contains the highly conserved catalytic glutamic acid residues [1].

1: Deciphering the three-domain architecture in schlafens and the structures and roles of human schlafen12 and serpinB12 in transcriptional regulation. Chen J, Kuhn LA; J Mol Graph Model. 2019;90:59-76. PMID:31026779

2: Schlafens: Emerging Proteins in Cancer Cell Biology. Al-Marsoummi S, Vomhof-DeKrey EE, Basson MD; Cells. 2021; [Epub ahead of print] PMID:34571887