Abstract:
:Sinorhizobium meliloti is a soil-dwelling alphaproteobacterium that engages in a nitrogen-fixing root nodule symbiosis with leguminous plants. Cell surface polysaccharides are important both for adapting to stresses in the soil and for the development of an effective symbiotic interaction. Among the polysaccharides characterized to date, the acidic exopolysaccharides I (EPS-I; succinoglycan) and II (EPS-II; galactoglucan) are particularly important for protection from abiotic stresses, biofilm formation, root colonization, and infection of plant roots. Previous genetic screens discovered mutants with impaired EPS production, allowing the delineation of EPS biosynthetic pathways. Here we report on a genetic screen to isolate mutants with mucoid colonial morphologies that suggest EPS overproduction. Screening with Tn5-110, which allows the recovery of both null and upregulation mutants, yielded 47 mucoid mutants, most of which overproduce EPS-I; among the 30 unique genes and intergenic regions identified, 14 have not been associated with EPS production previously. We identified a new protein-coding gene, emmD, which may be involved in the regulation of EPS-I production as part of the EmmABC three-component regulatory circuit. We also identified a mutant defective in EPS-I production, motility, and symbiosis, where Tn5-110 was not responsible for the mutant phenotypes; these phenotypes result from a missense mutation in rpoA corresponding to the domain of the RNA polymerase alpha subunit known to interact with transcription regulators.IMPORTANCE The alphaproteobacterium Sinorhizobium meliloti converts dinitrogen to ammonium while inhabiting specialized plant organs termed root nodules. The transformation of S. meliloti from a free-living soil bacterium to a nitrogen-fixing plant symbiont is a complex developmental process requiring close interaction between the two partners. As the interface between the bacterium and its environment, the S. meliloti cell surface plays a critical role in adaptation to varied soil environments and in interaction with plant hosts. We isolated and characterized S. meliloti mutants with increased production of exopolysaccharides, key cell surface components. Our diverse set of mutants suggests roles for exopolysaccharide production in growth, metabolism, cell division, envelope homeostasis, biofilm formation, stress response, motility, and symbiosis.
journal_name
J Bacterioljournal_title
Journal of bacteriologyauthors
Barnett MJ,Long SRdoi
10.1128/JB.00501-17subject
Has Abstractpub_date
2018-01-10 00:00:00issue
3eissn
0021-9193issn
1098-5530pii
JB.00501-17journal_volume
200pub_type
杂志文章abstract::Phosphotransacetylase and acetate kinase catalyze the activation of acetate to acetyl coenzyme A in the first step of methanogenesis from acetate in Methanosarcina thermophila. The genes encoding these enzymes (pta and ack) have been cloned and sequenced. They are arranged on the chromosome with pta upstream of ack (M...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.177.7.1699-1702.1995
更新日期:1995-04-01 00:00:00
abstract::The major sheath protein-encoding gene (mspA) of the oral spirochete Treponema maltophilum ATCC 51939(T) was cloned by screening a genomic library with an anti-outer membrane fraction antibody. The mspA gene encodes a precursor protein of 575 amino acids with a predicted molecular mass of 62.3 kDa, including a signal ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.181.3.1025-1029.1999
更新日期:1999-02-01 00:00:00
abstract::Rhodococcus sp. strain DK17 is capable of utilizing various derivatives of benzene and bicyclics containing both aromatic and alicyclic moieties as sole carbon and energy sources. Here, we present the 9,107,362-bp draft genome sequence of DK17 and its genomic analysis in comparison with other members of the genus Rhod...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00844-12
更新日期:2012-08-01 00:00:00
abstract::The conjugation system of the IncP alpha plasmid RK2/RP4 is encoded by transfer regions designated Tra1, Tra2, and Tra3. The Tra1 core region, cloned on plasmid pDG4 delta 22, consists of the origin of transfer (oriT) and 2.6 kilobases of flanking DNA providing IncP alpha plasmid-specific functions that allow pDG4 del...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.171.7.4100-4103.1989
更新日期:1989-07-01 00:00:00
abstract::Bladen, Howard A. (National Institute of Dental Health, Bethesda, Md.), and Edward G. Hampp. Ultrastructure of Treponema microdentium and Borrelia vincentii. J. Bacteriol. 87:1180-1191.-A small oral Treponema (FM) and Borrelia vincentii (N9) were harvested after 3 to 7 days of incubation and either embedded in Vestopa...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.87.5.1180-1191.1964
更新日期:1964-05-01 00:00:00
abstract::Emulsan, the polyanionic emulsifying agent synthesized by Acinetobacter calcoaceticus RAG-1, was depolymerized by an enzyme obtained from a soil bacterium YUV-1. The extracellular emulsan depolymerase was produced when strains RAG-1 and YUV-1 were grown together on agar medium. The enzyme was extracted from the agar a...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.156.1.161-167.1983
更新日期:1983-10-01 00:00:00
abstract::Upon cold shock, Escherichia coli cell growth transiently stops. During this acclimation phase, specific cold shock proteins (CSPs) are highly induced. At the end of the acclimation phase, their synthesis is reduced to new basal levels, while the non-cold shock protein synthesis is resumed, resulting in cell growth re...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.183.9.2808-2816.2001
更新日期:2001-05-01 00:00:00
abstract::Enterococcus faecalis ATCC 11700 is able to use arginine and the diamine agmatine as a sole energy source. Via the highly homologous deiminase pathways, arginine and agmatine are converted into CO2, NH3, and the end products ornithine and putrescine, respectively. In the arginine deiminase pathway, uptake of arginine ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.170.10.4522-4527.1988
更新日期:1988-10-01 00:00:00
abstract::Pore-forming colicins are soluble bacteriocins which form voltage-gated ion channels in the inner membrane of Escherichia coli. To reach their target, these colicins first bind to a receptor located on the outer membrane and then are translocated through the envelope. Colicins are subdivided into two groups according ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.177.17.4935-4939.1995
更新日期:1995-09-01 00:00:00
abstract::Autolysin-defective pneumococci treated with inhibitory concentrations of penicillin and other beta-lactam antibiotics continued to produce non-cross-linked peptidoglycan and cell wall teichoic acid polymers, the majority of which were released into the surrounding medium. The released cell wall polymers were those sy...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.157.2.507-513.1984
更新日期:1984-02-01 00:00:00
abstract::A novel method is described that allows a direct determination of the location of a portion of the dipicolinic acid (DPA) in spores. Ultraviolet (UV) irradiation is shown to cause cross-linkage of DPA to spore proteins which have the characteristics of membrane proteins. We suggest that DPA resides in the inner foresp...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.118.1.202-208.1974
更新日期:1974-04-01 00:00:00
abstract::Enterohemorrhagic Escherichia coli O157:H7 (EHEC) causes bloody diarrhea and hemolytic-uremic syndrome. EHEC encodes the sRNA chaperone Hfq, which is important in posttranscriptional regulation. In EHEC strain EDL933, Hfq acts as a negative regulator of the locus of enterocyte effacement (LEE), which encodes most of t...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.06141-11
更新日期:2011-12-01 00:00:00
abstract::In some media, Bacillus subtilis can maintain a prolonged stationary growth phase; however, in other media, nutrient depletion triggers a complex differentiation that culminates in production of a dormant endospore. This differentiation requires the expression of many genes. We found that during the stationary phase i...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.172.2.709-715.1990
更新日期:1990-02-01 00:00:00
abstract::The effect of heat shock on Myxococcus xanthus was investigated during both glycerol- and starvation-induced development. Cells heat shocked at 40 degrees C for 1 h prior to a development-inducing signal displayed an accelerated rate of myxospore formation at 30 degrees C. Additionally, M. xanthus cells heat shocked p...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.170.11.5200-5207.1988
更新日期:1988-11-01 00:00:00
abstract::Sneathia amnii is a poorly characterized emerging pathogen that has been implicated in amnionitis and urethritis. We found that S. amnii damages fetal membranes, and we identified and purified a cytotoxic exotoxin that lyses human red blood cells and damages cells from fetal membranes. The gene appears to be cotranscr...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.00162-20
更新日期:2020-06-09 00:00:00
abstract::The structural properties required for the binding of peptide substrates to the Escherichia coli periplasmic protein involved in oligopeptide transport were surveyed by measuring the ability of different peptides to compete for binding in an equilibrium dialysis assay with the tripeptide Ala-Phe-[3H]Gly. The protein s...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.168.2.775-779.1986
更新日期:1986-11-01 00:00:00
abstract::Triggering of germination in Bacillus megaterium QM B1551 spores with D-glucose was studied. First, the interaction of glucose with spores for less than 1 min resulted in triggering almost 90% of the spores after the glucose was removed by dilution. Therefore only a brief time is needed for glucose to trigger germinat...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.138.2.442-445.1979
更新日期:1979-05-01 00:00:00
abstract::The presence of the altered lysine transfer ribonucleic acid (tRNA) in Bacillus subtilis spores is strongly dependent on the medium on which the cells were sporulated. Cells sporulated on synthetic media or dilute complex media contain little or none of the new component, whereas those sporulated on concentrated compl...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.94.1.125-130.1967
更新日期:1967-07-01 00:00:00
abstract::Valentine, R. C. (University of Illinois, Urbana), H. Drucker, and R. S. Wolfe. Glyoxylate fermentation by Streptococcus allantoicus. J. Bacteriol. 87:241-246. 1964.-Extracts of Streptococcus allantoicus were found to degrade glyoxylate, yielding tartronic semialdehyde and CO(2). Tartronic semialdehyde was prepared ch...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.87.2.241-246.1964
更新日期:1964-02-01 00:00:00
abstract::A method consisting of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and subsequent detection of endoglucanases by blotting with a polyclonal antibody against endoglucanase I was used to investigate the effect of induction and carbon catabolite derepression on the synthesis of multiple forms of endoglucana...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.170.8.3689-3693.1988
更新日期:1988-08-01 00:00:00
abstract::Oligopeptidase B (OpdB) is a serine peptidase broadly distributed among unicellular eukaryotes, gram-negative bacteria, and spirochetes which has emerged as an important virulence factor and potential therapeutic target in infectious diseases. We report here the cloning and expression of the opdB homologue from Salmon...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.184.12.3329-3337.2002
更新日期:2002-06-01 00:00:00
abstract::Krebs cycle enzyme activity in Bacillus subtilis was examined under aerobic and anaerobic conditions. Citrate synthase and aconitase activities in cells grown anaerobically in the presence of nitrate were reduced by as much as 10- and 30-fold, respectively, from levels observed under aerobic culture conditions. The ma...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.180.13.3304-3311.1998
更新日期:1998-07-01 00:00:00
abstract::More than 98% of reported human listeriosis cases are caused by Listeria monocytogenes serotypes within lineages I and II. Serotypes within lineage III (4a and 4c) are commonly isolated from environmental and food specimens. We report the first complete genome sequence of a lineage III isolate, HCC23, which will be us...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.05236-11
更新日期:2011-07-01 00:00:00
abstract::Spores were isolated from the filamentous cyanobacterium Anabaena cylindrica, and their deoxyribonucleic acid, ribonucleic acid, and protein compositions were determined. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.129.2.1154-1155.1977
更新日期:1977-02-01 00:00:00
abstract::SopE is a bacteriophage-encoded effector protein of Salmonella enterica serovar Typhimurium that is translocated into the cytosol of eukaryotic cells by a type III secretion system (TTSS) (W.-D. Hardt, H. Urlaub, and J. E. Galán, Proc. Natl. Acad. Sci. USA 95:2574-2579, 1998; M. W. Wood, R. Rosqvist, P. B. Mullan, M. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.185.24.7279-7284.2003
更新日期:2003-12-01 00:00:00
abstract::Twenty-six FliF monomers assemble into the MS ring, a central motor component of the bacterial flagellum that anchors the structure in the inner membrane. Approximately 100 amino acids at the C terminus of FliF are exposed to the cytoplasm and, through the interaction with the FliG switch protein, a component of the f...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.185.5.1624-1633.2003
更新日期:2003-03-01 00:00:00
abstract::Cells of the cyanobacterium Anabaena variabilis starved for phosphate for 3 days took up phosphate at about 100 times the rate of unstarved cells. Kinetic data suggested that a new transport system had been induced by starvation for phosphate. The inducible phosphate transport system was quickly repressed by addition ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.170.3.1143-1147.1988
更新日期:1988-03-01 00:00:00
abstract::Neisseria meningitidis serogroup B strain M986 was examined for the involvement of lipid intermediate(s) participating in the biosynthesis of the sialic acid capsular polysaccharide. The addition of exogenous undecaprenyl phosphate, phosphatidylethanolamine, or phosphatidylglycerol to particulate membranes, in the pre...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.161.3.861-867.1985
更新日期:1985-03-01 00:00:00
abstract::The 5,10-methylenetetrahydrofolate dehydrogenase of heterotrophically grown Peptostreptococcus productus Marburg was purified to apparent homogeneity. The purified enzyme catalyzed the reversible oxidation of methylenetetrahydrofolate with NADP+ as the electron acceptor at a specific activity of 627 U/mg of protein. T...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/jb.173.4.1414-1419.1991
更新日期:1991-02-01 00:00:00
abstract::Mutants defective in uptake or utilization of a given metabolite can readily be obtained from facultative auxotrophs (for that metabolite) by penicillin enrichment under nonpermissive conditions in the presence of a low level of the required metabolite. ...
journal_title:Journal of bacteriology
pub_type: 杂志文章
doi:10.1128/JB.121.3.1216-1218.1975
更新日期:1975-03-01 00:00:00