Abstract:
:Recent footprinting, sedimentation and neutron-scattering results obtained in vivo or on pre-translocation and post-translocation ribosomal complexes are integrated with cross-linking and immunoelectron microscopy information. It is proposed that the 30S subunit pulses during translocation and that its pre- and post-translocation structures are not necessarily identical. Accordingly, translocation is characterized by three consecutive conformational states of the 30S and 50S subunits. State 1 (the pre-translocation state) lasts until the elongation factor EF-G.GTP complex binds to the ribosome or adopts the GTPase conformation. State 2 (the translocation state, or the peak or plateau of the pulse) follows and lasts until EF-G adopts a subsequent conformation or is released from the ribosome. State 3 (the post-translocation state) ensues and lasts until A (aminoacyl) site binding of aminoacyl-tRNA. In state 2, 16S RNA hairpins 26 and 33-33A, located in the platform and the head of the 30S subunit, respectively, become kinked or twisted, and residue A1503, near the decoding site, becomes exposed. A platform twist is associated with P (peptide) to E (exit) site tRNA movements and a head twist with pivoting of the peptidyl-tRNA elbow from the A to the P site, around a (retractable?) S19 domain. These twists result in an unlocking of the platform and the head from the 50S subunit. Exposure of A1503 is tentatively associated with movements of mRNA or tRNA anticodon stem-loops. These twisted or otherwise-exposed residues readopt their previous setting upon completion of translocation, i.e. states 1 and 3 of 16S RNA differ more from state 2 than from each other.(ABSTRACT TRUNCATED AT 250 WORDS)
journal_name
Mol Microbioljournal_title
Molecular microbiologyauthors
Laughrea Mdoi
10.1111/j.1365-2958.1994.tb00378.xsubject
Has Abstractpub_date
1994-03-01 00:00:00pages
999-1007issue
6eissn
0950-382Xissn
1365-2958journal_volume
11pub_type
杂志文章,评审abstract::Bacteria differ from eukaryotes by having the enzyme DNA gyrase, which catalyses the ATP-dependent negative supercoiling of DNA. Negative supercoils are essential for condensing chromosomes into an interwound (plectonemic) and branched structure known as the nucleoid. Topo-1 removes excess supercoiling in an ATP-indep...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2010.07394.x
更新日期:2010-12-01 00:00:00
abstract::The inner membrane protein CcmC (CytA) of Pseudomonas fluorescens ATCC17400, which has homologues in several bacteria and plant mitochondria, is needed for the biogenesis of cytochrome c. A CcmC-deficient mutant is also compromised in the production and utilization of pyoverdine, the high-affinity fluorescent sideroph...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.1998.01085.x
更新日期:1998-11-01 00:00:00
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journal_title:Molecular microbiology
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更新日期:2014-05-01 00:00:00
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journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2010.07329.x
更新日期:2010-10-01 00:00:00
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journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1992.tb01757.x
更新日期:1992-10-01 00:00:00
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pub_type: 杂志文章
doi:10.1046/j.1365-2958.2001.02594.x
更新日期:2001-09-01 00:00:00
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pub_type: 杂志文章,评审
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更新日期:2007-09-01 00:00:00
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journal_title:Molecular microbiology
pub_type: 杂志文章
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更新日期:2002-11-01 00:00:00
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更新日期:2006-08-01 00:00:00
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pub_type: 杂志文章
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更新日期:2011-09-01 00:00:00
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pub_type: 杂志文章
doi:10.1111/mmi.12336
更新日期:2013-09-01 00:00:00
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journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1992.tb00849.x
更新日期:1992-05-01 00:00:00
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journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.1997.3251690.x
更新日期:1997-04-01 00:00:00
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pub_type: 杂志文章
doi:10.1111/j.1365-2958.1996.tb02619.x
更新日期:1996-04-01 00:00:00
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pub_type: 杂志文章
doi:10.1111/mmi.13629
更新日期:2017-04-01 00:00:00
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journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.2003.03301.x
更新日期:2003-01-01 00:00:00
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journal_title:Molecular microbiology
pub_type: 杂志文章
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更新日期:1999-03-01 00:00:00
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journal_title:Molecular microbiology
pub_type: 杂志文章
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更新日期:1996-10-01 00:00:00
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journal_title:Molecular microbiology
pub_type: 杂志文章
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更新日期:1991-02-01 00:00:00
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更新日期:2003-02-01 00:00:00
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pub_type: 杂志文章
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更新日期:2011-11-01 00:00:00
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pub_type: 杂志文章
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更新日期:2012-10-01 00:00:00
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journal_title:Molecular microbiology
pub_type: 杂志文章
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更新日期:1991-07-01 00:00:00
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pub_type: 杂志文章
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更新日期:2008-12-01 00:00:00