A kinetic mechanism for the poly(C)-dependent ATPase of the Escherichia coli transcription termination protein, rho.

A study of the initial velocity kinetics of the Escherichia coli transcription termination protein rho, with respect to its poly(C)-dependent ATPase, indicates that this reaction occurs by an ordered sequential mechanism. Product inhibition and substrate analogue studies suggest that ATP binding must precede the binding of poly(C) and that the order of release of the products is ADP followed by Pi, then poly(C). A possible mechanism for relating the ATPase to the termination reaction of rho is discussed in relation to the model for rho proposed by Richardson (5).