This domain is found at the C-terminus of alkyl sulfatases. Together with the N-terminal catalytic domain, this domain forms a hydrophobic chute and may recruit hydrophobic substrates [1].

1: The crystal structure of SdsA1, an alkylsulfatase from Pseudomonas aeruginosa, defines a third class of sulfatases. Hagelueken G, Adams TM, Wiehlmann L, Widow U, Kolmar H, Tummler B, Heinz DW, Schubert WD; Proc Natl Acad Sci U S A. 2006;103:7631-7636. PMID:16684886