Abstract
The DNA sequences for the replication origins of the lambdoid bacteriophages .vphi.80, 434, .vphi.21, and .lambda.imm21 (identical to .vphi.21) were determined and compared to the .lambda. structure. Two presumptive elaborate binding sites for 2 initiator proteins were identified in their outer sections, while a replicational primer start site seems to be located in their centers.