2aki
From Proteopedia
(New page: 200px<br /><applet load="2aki" size="450" color="white" frame="true" align="right" spinBox="true" caption="2aki" /> '''Normal mode-based flexible fitted coordinate...) |
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| - | [[Image:2aki.gif|left|200px]]<br /><applet load="2aki" size=" | + | [[Image:2aki.gif|left|200px]]<br /><applet load="2aki" size="350" color="white" frame="true" align="right" spinBox="true" |
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'''Normal mode-based flexible fitted coordinates of a translocating SecYEG protein-conducting channel into the cryo-EM map of a SecYEG-nascent chain-70S ribosome complex from E. coli'''<br /> | '''Normal mode-based flexible fitted coordinates of a translocating SecYEG protein-conducting channel into the cryo-EM map of a SecYEG-nascent chain-70S ribosome complex from E. coli'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Secreted and membrane proteins are translocated across or into cell | + | Secreted and membrane proteins are translocated across or into cell membranes through a protein-conducting channel (PCC). Here we present a cryo-electron microscopy reconstruction of the Escherichia coli PCC, SecYEG, complexed with the ribosome and a nascent chain containing a signal anchor. This reconstruction shows a messenger RNA, three transfer RNAs, the nascent chain, and detailed features of both a translocating PCC and a second, non-translocating PCC bound to mRNA hairpins. The translocating PCC forms connections with ribosomal RNA hairpins on two sides and ribosomal proteins at the back, leaving a frontal opening. Normal mode-based flexible fitting of the archaeal SecYEbeta structure into the PCC electron microscopy densities favours a front-to-front arrangement of two SecYEG complexes in the PCC, and supports channel formation by the opening of two linked SecY halves during polypeptide translocation. On the basis of our observation in the translocating PCC of two segregated pores with different degrees of access to bulk lipid, we propose a model for co-translational protein translocation. |
==About this Structure== | ==About this Structure== | ||
| - | 2AKI is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http:// | + | 2AKI is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences 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=2AKI OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Ban, N.]] | [[Category: Ban, N.]] | ||
[[Category: Frank, J.]] | [[Category: Frank, J.]] | ||
| - | [[Category: III, C | + | [[Category: III, C L.Brooks.]] |
[[Category: Jenni, S.]] | [[Category: Jenni, S.]] | ||
[[Category: Mitra, K.]] | [[Category: Mitra, K.]] | ||
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[[Category: transport]] | [[Category: transport]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:28:19 2008'' |
Revision as of 14:28, 21 February 2008
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Normal mode-based flexible fitted coordinates of a translocating SecYEG protein-conducting channel into the cryo-EM map of a SecYEG-nascent chain-70S ribosome complex from E. coli
Overview
Secreted and membrane proteins are translocated across or into cell membranes through a protein-conducting channel (PCC). Here we present a cryo-electron microscopy reconstruction of the Escherichia coli PCC, SecYEG, complexed with the ribosome and a nascent chain containing a signal anchor. This reconstruction shows a messenger RNA, three transfer RNAs, the nascent chain, and detailed features of both a translocating PCC and a second, non-translocating PCC bound to mRNA hairpins. The translocating PCC forms connections with ribosomal RNA hairpins on two sides and ribosomal proteins at the back, leaving a frontal opening. Normal mode-based flexible fitting of the archaeal SecYEbeta structure into the PCC electron microscopy densities favours a front-to-front arrangement of two SecYEG complexes in the PCC, and supports channel formation by the opening of two linked SecY halves during polypeptide translocation. On the basis of our observation in the translocating PCC of two segregated pores with different degrees of access to bulk lipid, we propose a model for co-translational protein translocation.
About this Structure
2AKI is a Protein complex structure of sequences from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Structure of the E. coli protein-conducting channel bound to a translating ribosome., Mitra K, Schaffitzel C, Shaikh T, Tama F, Jenni S, Brooks CL 3rd, Ban N, Frank J, Nature. 2005 Nov 17;438(7066):318-24. PMID:16292303
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