2fsh
From Proteopedia
(New page: 200px<br /><applet load="2fsh" size="450" color="white" frame="true" align="right" spinBox="true" caption="2fsh, resolution 2.000Å" /> '''Complex SecA:AMP-PN...) |
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| - | [[Image:2fsh.jpg|left|200px]]<br /><applet load="2fsh" size=" | + | [[Image:2fsh.jpg|left|200px]]<br /><applet load="2fsh" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2fsh, resolution 2.000Å" /> | caption="2fsh, resolution 2.000Å" /> | ||
'''Complex SecA:AMP-PNP from Escherichia coli'''<br /> | '''Complex SecA:AMP-PNP from Escherichia coli'''<br /> | ||
==Overview== | ==Overview== | ||
| - | SecA is the preprotein translocase ATPase subunit and a superfamily 2 | + | SecA is the preprotein translocase ATPase subunit and a superfamily 2 (SF2) RNA helicase. Here we present the 2 A crystal structures of the Escherichia coli SecA homodimer in the apo form and in complex with ATP, ADP and adenosine 5'-[beta,gamma-imido]triphosphate (AMP-PNP). Each monomer contains the SF2 ATPase core (DEAD motor) built of two domains (nucleotide binding domain, NBD and intramolecular regulator of ATPase 2, IRA2), the preprotein binding domain (PBD), which is inserted in NBD and a carboxy-terminal domain (C-domain) linked to IRA2. The structures of the nucleotide complexes of SecA identify an interfacial nucleotide-binding cleft located between the two DEAD motor domains and residues critical for ATP catalysis. The dimer comprises two virtually identical protomers associating in an antiparallel fashion. Dimerization is mediated solely through extensive contacts of the DEAD motor domains leaving the C-domain facing outwards from the dimerization core. This dimerization mode explains the effect of functionally important mutations and is completely different from the dimerization models proposed for other SecA structures. The repercussion of these findings on translocase assembly and catalysis is discussed. |
==About this Structure== | ==About this Structure== | ||
| - | 2FSH is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with ANP as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 2FSH is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=ANP:'>ANP</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2FSH OCA]. |
==Reference== | ==Reference== | ||
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[[Category: seca]] | [[Category: seca]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:24:45 2008'' |
Revision as of 15:24, 21 February 2008
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Complex SecA:AMP-PNP from Escherichia coli
Overview
SecA is the preprotein translocase ATPase subunit and a superfamily 2 (SF2) RNA helicase. Here we present the 2 A crystal structures of the Escherichia coli SecA homodimer in the apo form and in complex with ATP, ADP and adenosine 5'-[beta,gamma-imido]triphosphate (AMP-PNP). Each monomer contains the SF2 ATPase core (DEAD motor) built of two domains (nucleotide binding domain, NBD and intramolecular regulator of ATPase 2, IRA2), the preprotein binding domain (PBD), which is inserted in NBD and a carboxy-terminal domain (C-domain) linked to IRA2. The structures of the nucleotide complexes of SecA identify an interfacial nucleotide-binding cleft located between the two DEAD motor domains and residues critical for ATP catalysis. The dimer comprises two virtually identical protomers associating in an antiparallel fashion. Dimerization is mediated solely through extensive contacts of the DEAD motor domains leaving the C-domain facing outwards from the dimerization core. This dimerization mode explains the effect of functionally important mutations and is completely different from the dimerization models proposed for other SecA structures. The repercussion of these findings on translocase assembly and catalysis is discussed.
About this Structure
2FSH is a Single protein structure of sequence from Escherichia coli with as ligand. Full crystallographic information is available from OCA.
Reference
Structure of dimeric SecA, the Escherichia coli preprotein translocase motor., Papanikolau Y, Papadovasilaki M, Ravelli RB, McCarthy AA, Cusack S, Economou A, Petratos K, J Mol Biol. 2007 Mar 9;366(5):1545-57. Epub 2006 Dec 23. PMID:17229438
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