A physical map of the group A streptococcal pyrogenic exotoxin bacteriophage T12 genome

Abstract

A physical map of group A streptococcal bacteriophage T12 was constructed with restriction endonucleases SalI, PstI, and EcoRI. The map is circularly permuted with a total length of 36.0 kb. Sub-molar quantities of certain restriction fragments, some of very precise MW and some of heterogeneous MW, were observed. This observation, together with mapping data, suggests that DNA packaging is intiated at a precise site on a concatemeric precursor and proceeds for a limited number of rounds. © 1983 Springer-Verlag.