This domain is associated with proteins from viruses, bacteria and eukaryotes. In the latter two taxonomic groups some of the proteins are annotated as either sialic acid-specific 9-O-acetylesterase (EC:3.1.1.53) or acetylxylan esterase related enzyme. The function of this domain is unknown.
Bitto E, Bingman CA, McCoy JG, Allard ST, Wesenberg GE, Phillips GN Jr.
The structure at 1.6 Angstroms resolution of the protein product of the At4g34215 gene from Arabidopsis thaliana.
Acta Crystallogr. D Biol. Crystallogr. 61 2005 1655-61
[PubMed: 16301800] http://dx.doi.org/10.1107/S0907444905034074