New Frontiers in the Study of Gene Functions

The heat-shock proteins in E. coli are transiently overexpressed af- ter shift to a higher growth temperature. The genes that encode the HSPs are preceded by promoters transcribed in vitro by a form of RNA poly- 32 32 merase holoenzyme containing a 32-kd a subunit (Ea ). The a subunit is encoded by the rpoH (htpR) gene, previously identified as a positive 32 effector of the heat-shock response. Our evidence suggests that Ea is the enzyme that transcribes heat-shock genes at all temperatures...