GTP binding and hydrolysis by the signal recognition particle during initiation of protein translocation

Miller, Joshua D.; Wilhelm, Heike; Gierasch, Lila M.; Gilmore, Reid; Walter, Peter

doi:10.1038/366351a0

Cited by 182 publications

(180 citation statements)

References 30 publications

Supporting

Mentioning

168

Contrasting

Unclassified

Order By: Relevance

“…In early work, we also showed that synthetic peptides corresponding to functional signal sequences modulate the GTPase activity of SRP/SRP receptor, while nonfunctional peptides do not. 30 Subsequent experiments in our lab 31 brought these results into question because of artifactual interactions between the signal peptides and the RNA SRP component; nonetheless, this research study paved the way for our ongoing studies of SRP-signal peptide interaction (see later).…”

Section: Signal Peptide Conformations and Membrane Interactionsmentioning

confidence: 99%

Use of synthetic signal sequences to explore the protein export machinery

Clérico¹,

Maki²,

Gierasch³

2008

Biopolymers

View full text Add to dashboard Cite

The information for correct localization of newly synthesized proteins in both prokaryotes and eukaryotes resides in self‐contained, often transportable targeting sequences. Of these, signal sequences specify that a protein should be secreted from a cell or incorporated into the cytoplasmic membrane. A central puzzle is presented by the lack of primary structural homology among signal sequences, although they share common features in their sequences. Synthetic signal peptides have enabled a wide range of studies of how these “zipcodes” for protein secretion are decoded and used to target proteins to the protein machinery that facilitates their translocation across and integration into membranes. We review research on how the information in signal sequences enables their passenger proteins to be correctly and efficiently localized. Synthetic signal peptides have made possible binding and crosslinking studies to explore how selectivity is achieved in recognition by the signal sequence‐binding receptors, signal recognition particle, or SRP, which functions in all organisms, and SecA, which functions in prokaryotes and some organelles of prokaryotic origins. While progress has been made, the absence of atomic resolution structures for complexes of signal peptides and their receptors has definitely left many questions to be answered in the future. © 2007 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 90: 307–319, 2008.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com

show abstract

Section: Signal Peptide Conformations and Membrane Interactionsmentioning

confidence: 99%

Use of synthetic signal sequences to explore the protein export machinery

Clérico¹,

Maki²,

Gierasch³

2008

Biopolymers

View full text Add to dashboard Cite

show abstract

“…Its features are very similar to those of the 54-kDa subunit of mammalian SRP (SRP54), which consists of structurally distinct, N-terminal G-and C-terminal M-domains (Bernstein et al, 1989;Romish et al, 1989). The G-domain contains three GTP-binding motifs and it may play an essential role mediating the interaction between SRP and SRP receptor (Miller et al, 1993). The M-domain is characterized by a high content of methionine residues.…”

mentioning

confidence: 99%

Identification of a Region Required for Binding to Presecretory Protein in Bacillus Subtilis Ffh, A Homologue of the 54‐kDa Subunit of Mammalian Signal Recognition Particle

Takamatsu

Bunai

Horinaka

et al. 1997

European Journal of Biochemistry

View full text Add to dashboard Cite

Bacillus subtilis Ffh protein is a homologue of the 54-kDa subunit of mammalian signal recognition particle (SRP54). It contains three highly hydrophobic regions (hl, h2, and h3) in the C-terminal methionine-rich domain (M-domain). Two of the hydrophobic regions, h2 and h3, are essential for small cytoplasmic RNA (scRNA) binding [Kurita, K., Honda, K., Summa, S., Takamatsu, H., Nakamura, K., & Yamane, K. (1996) J. Biol. Chem. 271, 13 140-13 1461. Using purified presecretory proteins and mutant Ffh proteins, we identified a region required for presecretory protein binding in B. subtilis Ffh. Deletion of this region, which consisted of residues Ser311-Gly362 of B. subtilis Ffh, including a hydrophobic sequence (hl), reduced precursor binding activity. In contrast, deletions of residues Leu121 -Lys279, Lys364-Met446, or Leu338-Ser397 of B. subtilis Ffh did not. We also analyzed the mutant B. subtilis Ffh proteins, FfhQQQR and FfhQQQQ having wild-type residues 398 -401 (Arg-Arg-Lys-Arg) replaced with Gln,Arg and Gln,, respectively. FfhQQQR bound to both scRNA and presecretory protein. Although the FfhQQQQ mutation prevented binding to scRNA, binding to the precursor was not affected. FfhQQQR restored the growth of B. subtilis DF46 strain in whichfJh gene expression is regulated by an inducible promoter in the absence of an inducer, whereas FfhQQQQ did not. These results indicate that the region including h l is required for B. subtilis Ffh to bind to presecretory protein. The results also suggest that scRNA is required for the complete function of the B. subtilis SRP-like particle in vivo, although this protein is intrinsically capable of binding a signal peptide free from scRNA.

show abstract

“…The G domains of SRP54 and SR␣ define a distinct subfamily within the Ras-like G proteins (20), the SRP GTPases, which are structurally characterized by an insertion (I-box) in the effector region and a close interaction with the N domain (21, 22). The GTPases in both SRP54 and SR␣ stimulate each other upon complex formation and have been proposed to act as GTPase-activating proteins for each other (8,9).SRP function relies on the tightly controlled communication of SRP54 with external regulators (e.g., the ribosome, the SR, and the translocon) and on internal communication between the domains of SRP54. For example, the interaction of SRP with the ribosome increases the affinity of SRP54 for GTP (23).…”

mentioning

confidence: 99%

Crystal structure of the complete core of archaeal signal recognition particle and implications for interdomain communication

Rosendal

Wild

Montoya

et al. 2003

Proc. Natl. Acad. Sci. U.S.A.

117

View full text Add to dashboard Cite

Targeting of secretory and membrane proteins by the signal recognition particle (SRP) is evolutionarily conserved, and the multidomain protein SRP54 acts as the key player in SRP-mediated protein transport. Binding of a signal peptide to SRP54 at the ribosome is coordinated with GTP binding and subsequent complex formation with the SRP receptor. Because these functions are localized to distinct domains of SRP54, communication between them is essential. We report the crystal structures of SRP54 from the Archaeon Sulfolobus solfataricus with and without its cognate SRP RNA binding site (helix 8) at 4-Å resolution. The two structures show the flexibility of the SRP core and the position of SRP54 relative to the RNA. A long linker helix connects the GTPase (G domain) with the signal peptide binding (M) domain, and a hydrophobic contact between the N and M domains relates the signal peptide binding site to the G domain. Hinge regions are identified in the linker between the G and M domains (292-LGMGD) and in the N-terminal part of the M domain, which allow for structural rearrangements within SRP54 upon signal peptide binding at the ribosome. P rotein transport to or across the plasma membrane in bacteria and the endoplasmic reticulum in eukaryotes is mediated by the signal recognition particle (SRP), a ubiquitous ribonucleoprotein particle (for reviews see refs. 1-3). SRP recognizes amino-terminal signal sequences of newly synthesized polypeptides at the ribosome, and the ribosome nascent chain SRP complex is then targeted to the membrane by an interaction between SRP and its cognate receptor (SR). In the presence of the translocon the signal peptide is released (4-6) and the translating polypeptide is translocated across or inserted into the membrane. The SRP pathway is regulated by the concerted action of GTPases in both the SRP and the SR (7-11). GTP binding is a prerequisite for SRP͞SR interaction (7), and GTP hydrolysis in SRP and SR occurs after the signal peptide is released (8) and resolves the SRP͞SR complex (12).Although the SRP pathway is evolutionarily conserved, the composition of SRP and the SR varies widely. The complex mammalian SRP consists of six protein subunits (ranging from 9 to 72 kDa) and a 7SL RNA. In eubacteria SRP consists of only one protein subunit (Ffh, fifty-four-homologue) and a 4.5S RNA. SRP in archaea represents an intermediate between these two as only two polypeptides (homologues of SRP19 and SRP54) have been identified in archaeal genomes, and the SRP RNA of Ϸ310 nts resembles the mammalian 7SL RNA (for review see ref. 13). The SRP receptor consists of only one protein (FtsY, SR␣ homologue) in eubacteria and archaea, but two proteins (SR␣ and SR␤) in eukaryotes.SRP54 is the only protein subunit that is conserved in all SRPs, and thus it is the key player in protein transport. SRP54 is essential for binding signal peptides (14-16) at the ribosome and for GTP-dependent complex formation with the SR (17, 18). SRP54 is a multidomain protein that consists of an N-terminal N domain (a f...

show abstract

GTP binding and hydrolysis by the signal recognition particle during initiation of protein translocation

Cited by 182 publications

References 30 publications

Use of synthetic signal sequences to explore the protein export machinery

Use of synthetic signal sequences to explore the protein export machinery

Identification of a Region Required for Binding to Presecretory Protein in Bacillus Subtilis Ffh, A Homologue of the 54‐kDa Subunit of Mammalian Signal Recognition Particle

Crystal structure of the complete core of archaeal signal recognition particle and implications for interdomain communication

Contact Info

Product

Resources

About