Abstract:
:We previously identified three well-dispersed mutations, E978-K, F989-L and D1009-R within the haemolysin A signal region, located at positions -46, -35 and -15, with respect to the C-terminus, respectively. Each mutation reduces the efficiency of secretion two- to threefold leaving 30-45% of the wild-type activity. We have constructed by in vitro manipulations double mutants of HlyA carrying all combinations of these mutations and a triple mutant carrying all three mutations. The effects on secretion were determined and the results, including residual levels of secretion with the triple mutant of only 0.6%, compared with the wild type, indicated that these residues may interact to form a single function in the wild-type signal. To test this further, we developed a secretion competition assay in order to classify signal mutations. We demonstrated that a CIZ-HlyA fusion protein, containing the C-terminal 81 kDa of HlyA fused to virtually the whole LacZ protein, strongly inhibits the secretion of the wild-type HlyA co-expressed in the same cell. The properties of the fusion indicate that it blocks the translocator. The three mutations singly and in combinations were recombined in vitro into the 3'-end of the hybrid gene. In every case, the presence of a mutation in the secretion signal of the hybrid protein alleviated the inhibition of secretion of the co-expressed HlyA. All the mutations are therefore essentially recessive and we propose that they all affect an early function, probably recognition of the translocator, rather than a subsequent step involved in translocation or final release of the toxin to the medium. This would indicate that residues involved in recognition (or steps leading to recognition) extend from at least -15 to -46 with respect to the HlyA C-terminus.
journal_name
Mol Microbioljournal_title
Molecular microbiologyauthors
Kenny B,Chervaux C,Holland IBdoi
10.1111/j.1365-2958.1994.tb00293.xsubject
Has Abstractpub_date
1994-01-01 00:00:00pages
99-109issue
1eissn
0950-382Xissn
1365-2958journal_volume
11pub_type
杂志文章abstract::Crs5 is a Saccharomyces cerevisiae Metallothionein (MT), non-homologous to the paradigmatic Cu-thionein Cup1. Although considered a secondary copper-resistance agent, we show here that it determines survival under zinc overload in a CUP1-null background. Its overexpression prevents the deleterious effects exhibited by...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2006.05510.x
更新日期:2007-01-01 00:00:00
abstract::Hybrid genes were constructed to express bifunctional hybrid proteins in which staphyloccal nuclease A with or without an amino-terminal OmpA signal sequence was fused with TEM beta-lactamase (at the carboxyl terminal side) using the signal peptide of the major outer membrane lipoprotein of Escherichia coli as an inte...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1994.tb00360.x
更新日期:1994-03-01 00:00:00
abstract::The 9.5 kb virB operon is the largest of the six major operons in the Ti plasmid vir region. This operon contains eleven genes, the largest of which is virB4. This gene encodes an 84 kDa protein whose function has not been identified. Its roles in conferring virulence on Agrobacterium tumefaciens and in the T-DNA tran...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1994.tb00338.x
更新日期:1994-02-01 00:00:00
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pub_type: 杂志文章
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更新日期:2000-09-01 00:00:00
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pub_type: 杂志文章
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更新日期:2010-01-01 00:00:00
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pub_type: 杂志文章
doi:10.1111/mmi.12890
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pub_type: 杂志文章
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更新日期:2003-10-01 00:00:00
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journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1992.tb01463.x
更新日期:1992-10-01 00:00:00
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pub_type: 杂志文章
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更新日期:2010-03-01 00:00:00
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pub_type: 杂志文章
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pub_type: 杂志文章
doi:10.1046/j.1365-2958.2002.03119.x
更新日期:2002-09-01 00:00:00
abstract::Agrobacterium tumefaciens uses a type IV secretion (T4S) system composed of VirB proteins and VirD4 to deliver oncogenic DNA (T-DNA) and protein substrates to susceptible plant cells during the course of infection. Here, by use of the Transfer DNA ImmunoPrecipitation (TrIP) assay, we present evidence that the mobiliza...
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pub_type: 杂志文章
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更新日期:2005-10-01 00:00:00
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journal_title:Molecular microbiology
pub_type: 杂志文章,评审
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更新日期:1999-04-01 00:00:00
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pub_type: 杂志文章
doi:10.1111/mmi.13942
更新日期:2018-05-01 00:00:00
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journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1991.tb02107.x
更新日期:1991-02-01 00:00:00
abstract::A promoter controlling expression of the pristinamycin multidrug resistance gene (ptr), originally isolated from Streptomyces pristinaespiralis, is inducible by many toxic compounds in various Streptomyces species. Studies of ptr promoter control were carried out in the heterologous host, Streptomyces lividans. In S. ...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1995.mmi_17061109.x
更新日期:1995-09-01 00:00:00
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journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2011.07545.x
更新日期:2011-03-01 00:00:00
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pub_type: 杂志文章
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更新日期:2000-10-01 00:00:00
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journal_title:Molecular microbiology
pub_type: 杂志文章
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pub_type: 杂志文章
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更新日期:2013-06-01 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:1997-06-01 00:00:00
abstract::The wrinkly spreader (WS) genotype of Pseudomonas fluorescens SBW25 colonizes the air-liquid interface of spatially structured microcosms resulting in formation of a thick biofilm. Its ability to colonize this niche is largely due to overproduction of a cellulosic polymer, the product of the wss operon. Chemical analy...
journal_title:Molecular microbiology
pub_type: 杂志文章
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更新日期:2003-10-01 00:00:00
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pub_type: 杂志文章
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更新日期:2006-01-01 00:00:00
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pub_type: 杂志文章,评审
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更新日期:2000-08-01 00:00:00
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journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.2002.02804.x
更新日期:2002-03-01 00:00:00
abstract::Visual inspection showed clear evidence of a history of intraspecies recombinational exchanges within the neighbouring meningococcal shikimate dehydrogenase (aroE) and glutamine synthetase (glnA) genes, which was supported by the non-congruence of the trees constructed from the sequences of these genes from different ...
journal_title:Molecular microbiology
pub_type: 杂志文章
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更新日期:1997-02-01 00:00:00
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journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1995.tb02224.x
更新日期:1995-01-01 00:00:00