Replication origin of Streptococcus pyogenes, organization and cloning in heterologous systems

The origin of DNA replication (oriC) of Streptococcus pyogenes, group A str eptococci (GAS), has been cloned in Escherichia coli and reintroduced by tr ansformation into other GAS strains. Transformation frequencies into GAS st rains with oriC-carrying plasmids occurred with unusually high frequencies. However, the oriC-containing plasmids in the new recipients were found to be unstable and had a tendency to integrate into the chromosome, even when a recA GAS strain was used as a recipient. The GAS oriC was able to direct the replication of autonomous plasmids in group B streptococcal recipients. The chromosomal organization of the oriC region of GAS relative to other b acterial species appears to be similar to oriC of Bacillus subtilis and oth er Gram-positive microorganisms. (C) 2000 Published by Elsevier Science B.V . on behalf of the Federation of European Microbiological Societies.