3bf0: Difference between revisions

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caption="3bf0, resolution 2.550Å" />

'''Crystal structure of Escherichia coli Signal peptide peptidase (SppA), Native crystals'''<br />

==Overview==

Signal peptide peptidase (Spp) is the enzyme responsible for cleaving the remnant signal peptides left behind in the membrane following Sec-dependent protein secretion. Spp activity appears to be present in all cell types, eukaryotic, prokaryotic and archaeal. Here we report the first structure of a signal peptide peptidase, that of the Escherichia coli SppA (SppA(EC)). SppA(EC) forms a tetrameric assembly with a novel bowl-shaped architecture. The bowl has a dramatically hydrophobic interior and contains four separate active sites that utilize a Ser/Lys catalytic dyad mechanism. Our structural analysis of SppA reveals that while in many Gram-negative bacteria as well as characterized plant variants, a tandem duplication in the protein fold creates an intact active site at the interface between the repeated domains, other species, particularly Gram-positive and archaeal organisms, encode half-size, unduplicated SppA variants that could form similar oligomers to their duplicated counterparts, but using an octamer arrangement and with the catalytic residues provided by neighboring monomers. The structure reveals a similarity in the protein fold between the domains in the periplasmic Ser/Lys protease SppA and the monomers seen in the cytoplasmic Ser/His/Asp protease ClpP. We propose that SppA may, in addition to its role in signal peptide hydrolysis, have a role in the quality assurance of periplasmic and membrane-bound proteins, similar to the role that ClpP plays for cytoplasmic proteins.

==About this Structure==

3BF0 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3BF0 OCA].

==Reference==

Crystal structure of a bacterial signal Peptide peptidase., Kim AC, Oliver DC, Paetzel M, J Mol Biol. 2008 Feb 15;376(2):352-66. Epub 2007 Dec 4. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=18164727 18164727]

[[Category: Escherichia coli]]

[[Category: Single protein]]

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[[Category: transmembrane]]

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@@ Line 2: / Line 2: @@
 caption="3bf0, resolution 2.550&Aring;" />
 '''Crystal structure of Escherichia coli Signal peptide peptidase (SppA), Native crystals'''<br />
+==Overview==
+Signal peptide peptidase (Spp) is the enzyme responsible for cleaving the remnant signal peptides left behind in the membrane following Sec-dependent protein secretion. Spp activity appears to be present in all cell types, eukaryotic, prokaryotic and archaeal. Here we report the first structure of a signal peptide peptidase, that of the Escherichia coli SppA (SppA(EC)). SppA(EC) forms a tetrameric assembly with a novel bowl-shaped architecture. The bowl has a dramatically hydrophobic interior and contains four separate active sites that utilize a Ser/Lys catalytic dyad mechanism. Our structural analysis of SppA reveals that while in many Gram-negative bacteria as well as characterized plant variants, a tandem duplication in the protein fold creates an intact active site at the interface between the repeated domains, other species, particularly Gram-positive and archaeal organisms, encode half-size, unduplicated SppA variants that could form similar oligomers to their duplicated counterparts, but using an octamer arrangement and with the catalytic residues provided by neighboring monomers. The structure reveals a similarity in the protein fold between the domains in the periplasmic Ser/Lys protease SppA and the monomers seen in the cytoplasmic Ser/His/Asp protease ClpP. We propose that SppA may, in addition to its role in signal peptide hydrolysis, have a role in the quality assurance of periplasmic and membrane-bound proteins, similar to the role that ClpP plays for cytoplasmic proteins.
 ==About this Structure==
 BF0 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3BF0 OCA].
+==Reference==
+Crystal structure of a bacterial signal Peptide peptidase., Kim AC, Oliver DC, Paetzel M, J Mol Biol. 2008 Feb 15;376(2):352-66. Epub 2007 Dec 4. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=18164727 18164727]
 [[Category: Escherichia coli]]
 [[Category: Single protein]]
@@ Line 16: / Line 22: @@
 [[Category: transmembrane]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Wed Jan 23 11:37:44 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 19:05:18 2008''