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Autonomously replicating sequences
Introduction
An autonomously replicating sequence (ARS) contains the origin of replication in the yeast genome. It contains four regions (A, B1, B2, and B3), named in order of their effect on plasmid stability; when these regions are mutated, replication does not initiate.
Element A is highly conserved, consisting of the consensus sequence:
5'- T/A T T T A Y R T T T T/A -3'
(where Y is either pyrimidine and R is either purine). When this element is mutated, the ARS loses all activity.