[Guanyl cyclase activity in the EF-T elongation factor of Escherichia coli]

Highly purified EF-Ts from E. coli does contain guanylate cyclase activity, which is absent from other purified transfer factors, such as EF-Tu and EF-G. Guanylate cyclase activity has been characterized by its sensitivity to inhibitors and substrate specificity. Although the physicochemical properties of guanylate cyclase are closely related to those of EF-Ts, it does not appear to be a contaminant of this transfer factor, but a specific enzyme. The possible role of guanylate cyclase in protein synthesis is discussed.