This family of proteins specific to thermoacidophile archaea includes STK_08120 from Sulfurisphaera tokodaii. This protein shows three alpha-helices and a seven-stranded beta-sheet. It may function as a carrier of fatty acids in their biosynthesis, metabolism, and/or intracellular transport processes [1].

1: A thermoacidophile-specific protein family, DUF3211, functions as a fatty acid carrier with novel binding mode. Miyakawa T, Sawano Y, Miyazono K, Miyauchi Y, Hatano K, Tanokura M; J Bacteriol. 2013;195:4005-4012. PMID:23836863