Abstract
Addition of yeast hexokinase and glucose at various time points of the pre-mRNA splicing reaction rapidly depleted ATP and inhibited further progress of the reaction, indicating that ATP is required for both the first and second steps of splicing. ATP analogues, p-fluorosulfonylbenzoy1-5'-adenosine (FSBA) and 7-chloro-4-nitrobenzo-2-oxa-1, 3-diazole (NBD-Cl), which can modify amino acids at the ATP-binding site of a protein, inactivated the splicing activity of the nuclear extract. While the inactivation by the former was irreversible, the splicing activity was complemented by a Micrococcal nucleasetreated extract. This ATP analogue (FSBA) may be a useful tool for identification of ATP-dependent splicing factors.
