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Structures of the signal recognition particle receptor from the archaeon Pyrococcus furiosus: implications for the targeting step at the membrane.

Egea PF, Tsuruta H, de Leon GP, Napetschnig J, Walter P, Stroud RM - PLoS ONE (2008)

Bottom Line: The basic charges on the surface of this helix are likely to regulate interactions at the membrane.Small angle X-ray scattering and analytical ultracentrifugation indicate that the crystal structure of Pfu-FtsY correlates well with the average conformation in solution.Based on previous structures of two sub-complexes, we propose a model of the core of archeal and eukaryotic SRP*SR targeting complexes.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, California, USA. pascal@msg.ucsf.edu

ABSTRACT
In all organisms, a ribonucleoprotein called the signal recognition particle (SRP) and its receptor (SR) target nascent proteins from the ribosome to the translocon for secretion or membrane insertion. We present the first X-ray structures of an archeal FtsY, the receptor from the hyper-thermophile Pyrococcus furiosus (Pfu), in its free and GDP*magnesium-bound forms. The highly charged N-terminal domain of Pfu-FtsY is distinguished by a long N-terminal helix. The basic charges on the surface of this helix are likely to regulate interactions at the membrane. A peripheral GDP bound near a regulatory motif could indicate a site of interaction between the receptor and ribosomal or SRP RNAs. Small angle X-ray scattering and analytical ultracentrifugation indicate that the crystal structure of Pfu-FtsY correlates well with the average conformation in solution. Based on previous structures of two sub-complexes, we propose a model of the core of archeal and eukaryotic SRP*SR targeting complexes.

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Related in: MedlinePlus

The FtsY from Pyrococcus furiosus.(A) Sequence alignment of FtsY/SRs of known structure including Pfu, Thermus aquaticus (Taq), Thermotoga maritima (Tma), Mycoplasma mycoides (Mmyc) and Arabidopsis thaliana (Atha) (chloroplast). The protease sensitive sites observed in E.coli and Taq FtsYs upon FtsY•Ffh complex formation are indicated (x). The ELEX2LX3D in the N domain is indicated. (B) Overall structure of the apo monomer of Pfu-FtsY. Two views related by a 180° rotation along a vertical axis are shown. The secondary structure elements of Pfu-FtsY are indicated. α-helices and conserved motifs of the SRP/SR-GTPases subfamily are labeled.
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pone-0003619-g001: The FtsY from Pyrococcus furiosus.(A) Sequence alignment of FtsY/SRs of known structure including Pfu, Thermus aquaticus (Taq), Thermotoga maritima (Tma), Mycoplasma mycoides (Mmyc) and Arabidopsis thaliana (Atha) (chloroplast). The protease sensitive sites observed in E.coli and Taq FtsYs upon FtsY•Ffh complex formation are indicated (x). The ELEX2LX3D in the N domain is indicated. (B) Overall structure of the apo monomer of Pfu-FtsY. Two views related by a 180° rotation along a vertical axis are shown. The secondary structure elements of Pfu-FtsY are indicated. α-helices and conserved motifs of the SRP/SR-GTPases subfamily are labeled.

Mentions: We crystallized and solved the X-ray structures of the apo and GDP•magnesium forms of Pfu-FtsY. The structures were solved at 2.2 and 2.0Å resolution for the apo and nucleotide-bound proteins, respectively (Table 1 and Material and Methods). The apo receptor was crystallized in two different crystallization conditions in absence of guanine nucleotide and its structure solved de novo using single wavelength anomalous dispersion of selenium; the structure is therefore not biased towards any of the previously solved homologues. The overall structure of the apo receptor is shown in Figure 1 with all sequence motifs characteristic of SRP GTPases well defined.


Structures of the signal recognition particle receptor from the archaeon Pyrococcus furiosus: implications for the targeting step at the membrane.

Egea PF, Tsuruta H, de Leon GP, Napetschnig J, Walter P, Stroud RM - PLoS ONE (2008)

The FtsY from Pyrococcus furiosus.(A) Sequence alignment of FtsY/SRs of known structure including Pfu, Thermus aquaticus (Taq), Thermotoga maritima (Tma), Mycoplasma mycoides (Mmyc) and Arabidopsis thaliana (Atha) (chloroplast). The protease sensitive sites observed in E.coli and Taq FtsYs upon FtsY•Ffh complex formation are indicated (x). The ELEX2LX3D in the N domain is indicated. (B) Overall structure of the apo monomer of Pfu-FtsY. Two views related by a 180° rotation along a vertical axis are shown. The secondary structure elements of Pfu-FtsY are indicated. α-helices and conserved motifs of the SRP/SR-GTPases subfamily are labeled.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2572998&req=5

pone-0003619-g001: The FtsY from Pyrococcus furiosus.(A) Sequence alignment of FtsY/SRs of known structure including Pfu, Thermus aquaticus (Taq), Thermotoga maritima (Tma), Mycoplasma mycoides (Mmyc) and Arabidopsis thaliana (Atha) (chloroplast). The protease sensitive sites observed in E.coli and Taq FtsYs upon FtsY•Ffh complex formation are indicated (x). The ELEX2LX3D in the N domain is indicated. (B) Overall structure of the apo monomer of Pfu-FtsY. Two views related by a 180° rotation along a vertical axis are shown. The secondary structure elements of Pfu-FtsY are indicated. α-helices and conserved motifs of the SRP/SR-GTPases subfamily are labeled.
Mentions: We crystallized and solved the X-ray structures of the apo and GDP•magnesium forms of Pfu-FtsY. The structures were solved at 2.2 and 2.0Å resolution for the apo and nucleotide-bound proteins, respectively (Table 1 and Material and Methods). The apo receptor was crystallized in two different crystallization conditions in absence of guanine nucleotide and its structure solved de novo using single wavelength anomalous dispersion of selenium; the structure is therefore not biased towards any of the previously solved homologues. The overall structure of the apo receptor is shown in Figure 1 with all sequence motifs characteristic of SRP GTPases well defined.

Bottom Line: The basic charges on the surface of this helix are likely to regulate interactions at the membrane.Small angle X-ray scattering and analytical ultracentrifugation indicate that the crystal structure of Pfu-FtsY correlates well with the average conformation in solution.Based on previous structures of two sub-complexes, we propose a model of the core of archeal and eukaryotic SRP*SR targeting complexes.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, California, USA. pascal@msg.ucsf.edu

ABSTRACT
In all organisms, a ribonucleoprotein called the signal recognition particle (SRP) and its receptor (SR) target nascent proteins from the ribosome to the translocon for secretion or membrane insertion. We present the first X-ray structures of an archeal FtsY, the receptor from the hyper-thermophile Pyrococcus furiosus (Pfu), in its free and GDP*magnesium-bound forms. The highly charged N-terminal domain of Pfu-FtsY is distinguished by a long N-terminal helix. The basic charges on the surface of this helix are likely to regulate interactions at the membrane. A peripheral GDP bound near a regulatory motif could indicate a site of interaction between the receptor and ribosomal or SRP RNAs. Small angle X-ray scattering and analytical ultracentrifugation indicate that the crystal structure of Pfu-FtsY correlates well with the average conformation in solution. Based on previous structures of two sub-complexes, we propose a model of the core of archeal and eukaryotic SRP*SR targeting complexes.

Show MeSH
Related in: MedlinePlus