This family has a Rossmanoid fold, with a deep trefoil knot in its C-terminal region. It has structural similarity to RNA methyltransferases, and is likely to function as an S-adenosyl-L-methionine (SAM)-dependent RNA 2'-O methyltransferase [1].

1: Crystal structure of Thermotoga maritima SPOUT superfamily RNA methyltransferase Tm1570 in complex with S-adenosyl-L-methionine. Kim do J, Kim HS, Lee SJ, Suh SW; Proteins. 2009;74:245-249. PMID:18831037