Represses ulaG and the ulaABCDEF operon. Two ulaR binding sites have been identified in each promoter. Full activity requires simultaneous interaction of UlaR with both divergent promoters and seems to be dependent on repressor-mediated DNA loop formation, which is helped by the action of integration host factor. Cells lacking this gene show a more rapid utilization of L-ascorbate and are able to grow on L-ascorbate under microaerophilic conditions.