A cold sensitive dnaA mutant of E. coli which overinitiates chromosome replication at low temperature

Abstract

A heat resistant mutant of E. coli dnaAts46 was isolated, which grows normally only at temperatures above 39°. After a temperature shift from 42° to 32° the mutant overproduces DNA relative to protein. This is due to overinitiation of rounds of chromosome replication at low temperature, as indicated by hybridization and other experiments. The mutation is cotransduced by Pl with ilv and could not be separated from dnaAts46 by transduction.