3.6.5.4 GDP - 53 3.6.5.4 LamB signal peptide dose-dependent inhibition of GTPase activity 125194 3.6.5.4 additional information membrane association of FtsY is stabilized by blocking its GTPase activity 2 3.6.5.4 signal peptide isolated functional signal peptides bind nonspecifically to the RNA component of SRP and aggregate the entire signal recognition particle, leading to a loss of its intrinsic GTPase activity, this effect is an artifact of the high peptide concentrations and low salt conditions used in in vitro studies, signal sequences at the N-terminus of nascent chains in vivo do not exhibit this activity 34916