✵ crdS gene codes the Curdlan synthase. ✵ crdA gene codes a protein which assists translocation of nascent polymer across cytoplasmic membrane. ✵ crdC gene codes a protein which assists translocation of nascent polymer across the periplasm. crdA, crdC, crdS genes occupy a contiguous 4,948-bp region in Agrobacterium sp. ATCC31749.