This is a family of L-arabinose isomerases, AraA, EC:5.3.1.4. These enzymes catalyse the reaction: L-arabinose <=> L-ribulose. This reaction is the first step in the pathway of L-arabinose utilisation as a carbon source after entering the cell L-arabinose is converted into L-ribulose by the L-arabinose isomerases enzyme [1]. This is a C-terminal non catalytic domain.

1: The Bacillus subtilis L-arabinose (ara) operon: nucleotide sequence, genetic organization and expression. Sa-Nogueira I, Nogueira TV, Soares S, de Lencastre H; Microbiology 1997;143:957-969. PMID:9084180