Abstract:
:Genetic experiments have indicated that succinoglycan (EPS I), the acidic Calcofluor-binding exopolysaccharide, of the nitrogen-fixing bacterium Rhizobium meliloti strain Rm1021 is required for nodule invasion and possibly for later events in nodule development on alfalfa and other hosts. Fourteen exo loci on the second megaplasmid have been identified that are required for, or affect, the synthesis of EPS I. Mutations in certain of these loci completely abolish the production of EPS I and result in mutants that form empty Fix- nodules. We have identified two loci, exoR and exoS, that are involved in the regulation of EPS I synthesis in the free-living state. Certain exo mutations which completely abolish EPS I production are lethal in an exoR95 or exoS96 background. Histochemical analyses of the expression of exo genes during nodulation using exo::TnphoA fusions have indicated that the exo genes are expressed most strongly in the invasion zone. In addition, we have discovered that R. meliloti has a latent capacity to synthesize a second exopolysaccharide (EPS II) that can substitute for the role(s) of EPS I in nodulation of alfalfa but not of other hosts. Possible roles for exopolysaccharides in symbiosis are discussed.
journal_name
Biochem Soc Transjournal_title
Biochemical Society transactionsauthors
Reuber TL,Reed J,Glazebrook J,Glucksmann MA,Ahmann D,Marra A,Walker GCdoi
10.1042/bst0190636subject
Has Abstractpub_date
1991-08-01 00:00:00pages
636-41issue
3eissn
0300-5127issn
1470-8752journal_volume
19pub_type
杂志文章,评审abstract::Cytochrome P450 (CYP) enzymes represent a large superfamily that displays extraordinarily diverse substrate specificities. After a concise review about CYPs of the CYP1A subfamily, which plays a crucial role in procarcinogen activation, this paper presents segment-directed mutagenesis. This approach generates a librar...
journal_title:Biochemical Society transactions
pub_type: 杂志文章
doi:10.1042/0300-5127:0290128
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abstract::CoA (coenzyme A) and its derivatives have a critical role in regulating cardiac energy metabolism. This includes a key role as a substrate and product in the energy metabolic pathways, as well as serving as an allosteric regulator of cardiac energy metabolism. In addition, the CoA ester malonyl-CoA has an important ro...
journal_title:Biochemical Society transactions
pub_type: 杂志文章,评审
doi:10.1042/BST20140094
更新日期:2014-08-01 00:00:00
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journal_title:Biochemical Society transactions
pub_type: 杂志文章,评审
doi:10.1042/BST0350849
更新日期:2007-11-01 00:00:00
abstract::Growth and differentiation factor-5 (GDF-5) is a divergent member of the transforming growth factor-beta/bone morphogenetic protein (BMP) superfamily that is required for proper skeletal patterning and development in the vertebrate limb. Based on the homology of GDF-5 with other bone-inducing BMP family members, the i...
journal_title:Biochemical Society transactions
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更新日期:2000-01-01 00:00:00
abstract::[Ca(2+)](i) (intracellular Ca(2+) concentration) oscillations play a central role in the activation of T-lymphocytes by antigen. Oscillations in T-cells are absolutely dependent on Ca(2+) influx through store-operated CRAC channels (Ca(2+)-release-activated Ca(2+) channels), and evidence suggests that they arise from ...
journal_title:Biochemical Society transactions
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doi:10.1042/bst0310925
更新日期:2003-10-01 00:00:00
abstract::Recent progress in understanding the plant NE (nuclear envelope) has resulted from significant advances in identifying and characterizing the protein constituents of the membranes and nuclear pores. Here, we review recent findings on the membrane integral and membrane-associated proteins of the key domains of the NE, ...
journal_title:Biochemical Society transactions
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更新日期:2010-02-01 00:00:00
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journal_title:Biochemical Society transactions
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更新日期:1996-05-01 00:00:00
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journal_title:Biochemical Society transactions
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更新日期:2002-11-01 00:00:00
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journal_title:Biochemical Society transactions
pub_type: 杂志文章,评审
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更新日期:2011-12-01 00:00:00
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journal_title:Biochemical Society transactions
pub_type: 杂志文章,评审
doi:10.1042/BST0351195
更新日期:2007-11-01 00:00:00
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journal_title:Biochemical Society transactions
pub_type: 杂志文章
doi:
更新日期:2000-12-01 00:00:00
abstract::The analysis of deep sequencing data allows for a genome-wide overview of all the small RNA molecules (the 'sRNome') that are present in a single organism. In the present paper, we review the processing of CRISPR (clustered regularly interspaced short palindromic repeats) RNA, C/D box sRNA (small non-coding RNA) and t...
journal_title:Biochemical Society transactions
pub_type: 杂志文章,评审
doi:10.1042/BST20120276
更新日期:2013-02-01 00:00:00
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journal_title:Biochemical Society transactions
pub_type: 杂志文章,评审
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更新日期:2012-12-01 00:00:00
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journal_title:Biochemical Society transactions
pub_type: 杂志文章
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更新日期:2020-04-29 00:00:00
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journal_title:Biochemical Society transactions
pub_type: 杂志文章,评审
doi:10.1042/bst0320046
更新日期:2004-02-01 00:00:00
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journal_title:Biochemical Society transactions
pub_type: 杂志文章,评审
doi:10.1042/BST0361329
更新日期:2008-12-01 00:00:00
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journal_title:Biochemical Society transactions
pub_type: 杂志文章,评审
doi:10.1042/
更新日期:2002-04-01 00:00:00
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journal_title:Biochemical Society transactions
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journal_title:Biochemical Society transactions
pub_type: 杂志文章,评审
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更新日期:2014-08-01 00:00:00
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journal_title:Biochemical Society transactions
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更新日期:2014-08-01 00:00:00
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journal_title:Biochemical Society transactions
pub_type: 杂志文章,评审
doi:10.1042/BST20051327
更新日期:2005-12-01 00:00:00
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journal_title:Biochemical Society transactions
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更新日期:2008-12-01 00:00:00
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journal_title:Biochemical Society transactions
pub_type: 杂志文章
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更新日期:2014-04-01 00:00:00
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journal_title:Biochemical Society transactions
pub_type: 杂志文章,评审
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更新日期:2004-12-01 00:00:00
abstract::RNA pseudoknots are structural elements found in almost all classes of RNA. Pseudoknots form when a single-stranded region in the loop of a hairpin base-pairs with a stretch of complementary nucleotides elsewhere in the RNA chain. This simple folding strategy is capable of generating a large number of stable three-dim...
journal_title:Biochemical Society transactions
pub_type: 杂志文章,评审
doi:10.1042/BST0360684
更新日期:2008-08-01 00:00:00
abstract::The evolution of proteins is inseparably linked to their function. Because most biological processes involve a number of different proteins, it may become impossible to study the evolutionary properties of proteins in isolation. In the present article, we show how simple mechanistic models of biological processes can ...
journal_title:Biochemical Society transactions
pub_type: 杂志文章
doi:10.1042/BST0370762
更新日期:2009-08-01 00:00:00
abstract::Large single crystals (up to 1 mm in each dimension) of the B800-850 antenna complex from Rhodopseudomonas acidophila strain 10050 have been grown in the presence of beta-octyl-glucoside. These crystals have the space group R32 and unit cell dimensions of a = b = 119.9 A and c = 297.0 A. Recently we have improved our ...
journal_title:Biochemical Society transactions
pub_type: 杂志文章
doi:10.1042/bst0210039
更新日期:1993-02-01 00:00:00
abstract::PLUNC (palate, lung and nasal epithelium clone) is a small, secreted protein that is expressed in the oropharynx and upper airways of humans, mice and rats. We have described a family of at least 14 PLUNC genes localized on chromosome 20 (in humans), 2 (in mice) or 3 (in rats). These rapidly evolving proteins are stru...
journal_title:Biochemical Society transactions
pub_type: 杂志文章,评审
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更新日期:2003-08-01 00:00:00
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journal_title:Biochemical Society transactions
pub_type: 杂志文章,评审
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更新日期:2005-02-01 00:00:00
abstract::Enzymes of the 1-deoxy-D-xylulose 5-phosphate/2-C-methylerythritol 4-phosphate (DOXP/MEP) pathway are targets for new herbicides and antibacterial drugs. Until now, no inhibitors for the DOXP synthase have been known of. We show that one of the breakdown products of the herbicide clomazone affects the DOXP synthase. O...
journal_title:Biochemical Society transactions
pub_type: 杂志文章
doi:
更新日期:2000-12-01 00:00:00