Protein targeting by the signal recognition particle.
Protein targeting by the signal recognition particle (SRP) is universally conserved and starts with the recognition of a signal sequence in the context of a translating ribosome. SRP54 and FtsY, two multidomain proteins with guanosine triphosphatase (GTPase) activity, are the central elements of the SRP system. They have to coordinate the presence of a signal sequence with the presence of a vacant translocation channel in the membrane. For coordination the two GTPases form a unique, nearly symmetric heterodimeric complex in which the activation of GTP hydrolysis plays a key role for membrane insertion of substrate proteins. Recent results are integrated in an updated perception of the order of events in SRP-mediated protein targeting.
Grudnik
Przemyslaw
P
Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany.
Bange
Gert
G
Sinning
Irmgard
I
D000818:Animals; D001426:Bacterial Proteins / Q000502:physiology; D002736:Chloroplasts / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000502:physiology; D020558:GTP Phosphohydrolases / Q000378:metabolism; D006801:Humans; D008958:Models, Molecular; D021381:Protein Transport / Q000235:genetics*; D018160:Receptors, Cytoplasmic and Nuclear / Q000502:physiology; D018271:Signal Recognition Particle / Q000502:physiology*
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C082931:Ffh protein, E coli; C087406:FtsY protein, Bacteria; D018160:Receptors, Cytoplasmic and Nuclear; D018271:Signal Recognition Particle; D020558:GTP Phosphohydrolases