3.6.5.4	GDP + H2O	-	
3.6.5.4	GTP + H2O	-	
3.6.5.4	GTP + H2O	cotranslational protein targeting to the plasma membrane, the Ffh-4.5S RNA ribonucleoprotein complex and the FtsY protein, respectively, form a unique complex in which both Ffh and FtsY act as GTPase activating proteins for one another, resulting in a mutual stimulation of GTP hydrolysis by both proteins, 4.5S RNA modulates the conformation of the Ffh-FtsY complex and may regulate its GTPase activity during the SRP functional cycle	
3.6.5.4	GTP + H2O	Ffh mediates SRP-dependent, cotranslational protein targeting to the plasma membrane, Ffh and FtsY, the latter being the GTPase subunit of the bacterial SRP receptor, act as GTPase activating proteins for one another, resulting in reciprocal stimulation of GTP hydrolysis	
3.6.5.4	GTP + H2O	protein targeting by the SRP pathway, Ffh and FtsY, the GTPase subunit of the SRP receptor, reciprocally regulate each other’s GTPase activity, they interact only in a primed conformation which requires interdomain communication	
3.6.5.4	GTP + H2O	protein targeting to the plasma membrane	
3.6.5.4	GTP + H2O	protein targeting to the plasma membrane, signal recognition particle cycle, SRP and its receptor stimulate each other’s GTPase activity, GTP hydrolysis ensures unidirectional targeting of cargo through a translocation pore in the membrane	
3.6.5.4	GTP + H2O	the multidomain protein SRP54 acts as a key player in SRP-mediated protein transport, the GTPase drives the SRP cycle	
3.6.5.4	GTP + H2O	the signal recognition particle mediates the co-translational targeting of nascent proteins to the bacterial plasma membrane. During this process, two GTPases, one in the signal recognition particle and one in the signal recogition particle receptor, form a complex in which both proteins reciprocally activate the GTPase reaction of one another. Crystal structures of the complex of signal recognition particle and signal recogition particle receptor show that the two GTPases associate via an unusually extensive and highly cooperative interaction surface and form a composite active site at the interface. GTPase activation proceeds through a unique mechanism, stimulated by both interactions between the twinned GTP molecules across the dimer interface and by conformational rearrangements that position catalytic residues in each active site with respect to the bound substrate	
3.6.5.4	additional information	FlhF is dispensable for protein targeting and for growth and viability, it plays a minor role in cell motility, the flhF gene is located within the che/fla operon	
3.6.5.4	additional information	light-harvesting chlorophyll a/b binding proteins are posttranslationally targeted to the thylakoid membrane by cpSRP, a heterodimer formed by cpSRP54 and cpSRP43	
3.6.5.4	additional information	Rpl25p plays a critical role in the recruitment of signal recognition particle to the ribosome	
3.6.5.4	additional information	the cpFtsY membrane-binding motif plays a critical role in the intramolecular communication that regulates cpSRP receptor functions at the membrane	
3.6.5.4	additional information	the sensor protein KdpD requires the signal recognition particle for its targeting to the membrane, small amphiphilic region of 27 residues within the amino-terminal domain of KdpD (amino acids 22-48) is recognized by SRP and targets the protein to the membrane, depletion of the Ffh component of SRP largely inhibits KdpD insertion	
3.6.5.4	additional information	the signal recognition particle pathway is important for virulence factor secretion in Streptococcus pyogenes