Cloning and expression of a functional fucose‐specific lectin from an orange peel mushroom, Aleuria aurantia

Aleuria aurantialectin (AAL) shows sugar‐binding specificity for L‐fucose. A λgt11 expression library was constructed from A. aurantiapoly(A) RNA and screened with a polyclonal antiserum directed against AAL. An immunopositive clone carrying 1.3‐kb EcoRI fragment was obtained. The fragment encoded AAL, but lacked a nucleotide sequence corresponding to the two amino‐terminal amino acids. The 5′‐terminal part of the fragment was replaced with a chemically synthesized DNA fragment and inserted into an expression vector to yield a plasmid pKA‐1. Escherichia colicarrying pKA‐1 expressed functional AAL and the recombinant AAL showed the same immunological properties as those of natural AAL.