Abstract:
:Siderophore-mediated iron transport in Pseudomonas aeruginosa is dependent upon the cytoplasmic membrane-associated TonB1 energy coupling protein for activity. To assess the functional significance of the various regions of this molecule and to identify functionally important residues, the tonB1 gene was subjected to site-directed mutagenesis, and the influence on iron acquisition was determined. The novel N-terminal extension of TonB1, which is absent in all other examples of TonB, was required for TonB1 activity in both P. aeruginosa and Escherichia coli. Appending it to the N terminus of the nonfunctional (in P. aeruginosa) Escherichia coli TonB protein (TonB(Ec)) rendered TonB(Ec) weakly active in P. aeruginosa and did not compromise the activity of this protein in E. coli. Elimination of the membrane-spanning, presumed membrane anchor sequence of TonB1 abrogated TonB1 activity in P. aeruginosa and E. coli. Interestingly, however, a conserved His residue within the membrane anchor sequence, shown to be required for TonB(Ec) function in E. coli, was shown here to be essential for TonB1 activity in E. coli but not in P. aeruginosa. Several mutations within the C-terminal end of TonB1, within a region exhibiting the greatest similarity to other TonB proteins, compromised a TonB1 contribution to iron acquisition in both P. aeruginosa and E. coli, including substitutions at Tyr264, Glu274, Lys278, and Asp304. Mutations at Pro265, Gln293, and Val294 also impacted negatively on TonB1 function in E. coli but not in P. aeruginosa. The Asp304 mutation was suppressed by a second mutation at Glu274 of TonB1 but only in P. aeruginosa. Several TonB1-TonB(Ec) chimeras were constructed, and assessment of their activities revealed that substitutions at the N or C terminus of TonB1 compromised its activity in P. aeruginosa, although chimeras possessing an E. coli C terminus were active in E. coli.
journal_name
J Bacterioljournal_title
Journal of bacteriologyauthors
Zhao Q,Poole Kdoi
10.1128/jb.184.6.1503-1513.2002keywords:
subject
Has Abstractpub_date
2002-03-01 00:00:00pages
1503-13issue
6eissn
0021-9193issn
1098-5530journal_volume
184pub_type
杂志文章abstract::Sinorhizobium meliloti is a free-living soil bacterium which is capable of establishing a symbiotic relationship with the alfalfa plant (Medicago sativa). This symbiosis involves a network of bacterium-host signaling, as well as the potential for bacterium-bacterium communication, such as quorum sensing. In this study...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.184.13.3466-3475.2002
更新日期:2002-07-01 00:00:00
abstract::Fifteen low-temperature conditional division mutants of Escherichia coli K-12 was isolated. They grew normally at 39 degrees C but formed filaments at 30 degrees C. All exhibited a coordinated burst of cell division when the filaments were shifted to the permissive temperature (39 degrees C). None of the various agent...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.133.1.256-264.1978
更新日期:1978-01-01 00:00:00
abstract::The highly defective rho-15 mutant of Escherichia coli produces plasmid DNA that is 22% less negatively supercoiled than DNA from an isogenic wild-type strain (J. S. Fassler, G. F. Arnold, and I. Tessman, Mol. Gen. Genet. 204:424-429, 1986). We extended our measurements of plasmid superhelicity to additional rho mutan...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.170.9.4266-4271.1988
更新日期:1988-09-01 00:00:00
abstract::Synthesis of wild-type Neurospora crassa assimilatory nitrate reductase is induced in the presence of nitrate ions and repressed in the presence of ammonium ions. Effects of several Neurospora mutations on the regulation of this enzyme are shown: (i) the mutants, nit-1 and nit-3, involving separate lesions, lack reduc...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.133.2.671-679.1978
更新日期:1978-02-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.185.10.3101-3110.2003
更新日期:2003-05-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.120.1.441-449.1974
更新日期:1974-10-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.163.3.1038-1046.1985
更新日期:1985-09-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.125.2.545-555.1976
更新日期:1976-02-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.185.15.4326-4335.2003
更新日期:2003-08-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00891-06
更新日期:2007-02-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.161.1.285-291.1985
更新日期:1985-01-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.131.2.413-420.1977
更新日期:1977-08-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.169.8.3422-3428.1987
更新日期:1987-08-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.104.1.152-157.1970
更新日期:1970-10-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.91.4.1440-1445.1966
更新日期:1966-04-01 00:00:00
abstract::Generally nonchemotactic mutants of Escherichia coli and Salmonella typhimurium were analyzed by interspecies complementation tests to determine the functional correspondence between the che genes of these two organisms. The E. coli che region was introduced into Salmonella recipients by means of a series of F-prime e...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.139.1.107-114.1979
更新日期:1979-07-01 00:00:00
abstract::Reyranella massiliensis is an Alphaproteobacterium member of the class Rhodospirillaceae, growing in amoebae. We sequenced the genome of type strain 521(T). It is composed of a 5,792,218-bp chromosome and encodes 5,675 protein-coding genes and 53 RNA genes, including 3 rRNA genes. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.01260-12
更新日期:2012-10-01 00:00:00
abstract::Methanohalophilus strain Z7302 was previously isolated from a hypersaline environment and grows over a range of NaCl concentrations from 1.7 to 4.4 M. We examined the relationships between cell growth rate, cell volume, and intracellular solute concentrations with increasing salinity. This extremely halophilic methano...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.174.22.7474-7477.1992
更新日期:1992-11-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.157.1.330-333.1984
更新日期:1984-01-01 00:00:00
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pub_type: 杂志文章
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更新日期:2020-07-09 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
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更新日期:2007-05-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.175.6.1723-1734.1993
更新日期:1993-03-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00205-06
更新日期:2006-06-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.93.1.273-277.1967
更新日期:1967-01-01 00:00:00
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journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.186.5.1409-1414.2004
更新日期:2004-03-01 00:00:00
abstract::Decreased intracellular levels of FtsH, a membrane-bound ATPase, led to retardation of growth and protein export, as well as to an abnormal translocation of alkaline phosphatase that had been attached to a cytoplasmic domain of a multispanning membrane protein, SecY. The last phenotype is designated Std (stop transfer...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.178.4.1141-1145.1996
更新日期:1996-02-01 00:00:00
abstract::The inhibitory effect of fungitoxic derivatives of 1,4-oxathiin on substrate oxidation by the basidiomycete Ustilago maydis is diminished by a single-gene mutation (oxr). The difference between mutant and wild type is approximately the same on the basis of inhibition of either growth and operation of the tricarboxylic...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.110.3.809-817.1972
更新日期:1972-06-01 00:00:00
abstract::The importance of the physiological state of a culture of Saccharomyces cerevisiae for tolerance to sudden osmotic dehydration was studied, and it was investigated whether specific osmotolerance factors were demonstrable. The microcalorimeter was used to monitor growth, and different physiological states of the cultur...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.170.10.4562-4568.1988
更新日期:1988-10-01 00:00:00
abstract::Strain DCB-1 is a strict anaerobe capable of reductive dehalogenation. We elucidated metabolic processes in DCB-1 which may be related to dehalogenation and which further characterize the organism physiologically. Sulfoxy anions and CO2 were used by DCB-1 as catabolic electron acceptors. With suitable electron donors,...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.172.4.2065-2070.1990
更新日期:1990-04-01 00:00:00
abstract::The model archaeon Pyrococcus furiosus grows optimally near 100°C on carbohydrates and peptides. Its genome sequence (NCBI) was determined 12 years ago. A genetically tractable strain, COM1, was very recently reported, and here we describe its genome sequence. Of 1,909,827 bp in size, it is 1,571 bp longer (0.1%) than...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00439-12
更新日期:2012-08-01 00:00:00