Limited capacity for protein synthesis at zero degrees centigrade in Escherichia coli

Abstract

At 0 °C protein synthesis by Escherichia coli slows progressively and eventually stops. However, it is restored instantly to normal if the cells are warmed to 37 °C. The cause of the low-temperature defect appears to be an inability of free ribosomes to attach to messenger RNA. The evidence suggests that a ribosome has to be activated especially, once it has been released from the 3′ end of a messenger RNA strand, in order to permit its functional reattachment at the 5′-end of a new operon. This activation apparently proceeds too slowly at 0 °C to be effective in competition with inactivation processes. The low-temperature defect in protein synthesis could explain the well-known phenomenon of minimum growth temperature.