Alr0397 Is an Outer Membrane Transporter for the Siderophore Schizokinen in Anabaena sp. Strain PCC 7120

ABSTRACT Iron uptake in proteobacteria by TonB-dependent outer membrane transporters represents a well-explored subject. In contrast, the same process has been scarcely investigated in cyanobacteria. The heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120 is known to secrete the siderophore schizokinen, but its transport system has remained unidentified. Inspection of the genome of strain PCC 7120 shows that only one gene encoding a putative TonB-dependent iron transporter, namely alr0397, is positioned close to genes encoding enzymes involved in the biosynthesis of a hydroxamate siderophore. The expression of alr0397, which encodes an outer membrane protein, was elevated under iron-limited conditions. Inactivation of this gene caused a moderate phenotype of iron starvation in the mutant cells. The characterization of the mutant strain showed that Alr0397 is a TonB-dependent schizokinen transporter (SchT) of the outer membrane and that alr0397 expression and schizokinen production are regulated by the iron homeostasis of the cell.

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Isolation and characterization of the gene encoding the principal sigma factor of the vegetative cell RNA polymerase from the cyanobacterium Anabaena sp. strain PCC 7120.

Journal of Bacteriology ◽

10.1128/jb.173.8.2442-2450.1991 ◽

1991 ◽

Vol 173 (8) ◽

pp. 2442-2450 ◽

Cited By ~ 71

Author(s):

B Brahamsha ◽

R Haselkorn

Keyword(s):

Rna Polymerase ◽

Sigma Factor ◽

Vegetative Cell ◽

Gene Encoding ◽

Isolation And Characterization ◽

Cyanobacterium Anabaena ◽

Anabaena Sp ◽

Pcc 7120

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Characterization of Genes Encoding Multi-domain Proteins in the Genome of the Filamentous Nitrogen-fixing Cyanobacterium Anabaena sp. Strain PCC 7120

DNA Research ◽

10.1093/dnares/8.6.271 ◽

2001 ◽

Vol 8 (6) ◽

pp. 271-284 ◽

Cited By ~ 66

Author(s):

M. Ohmori

Keyword(s):

Nitrogen Fixing ◽

Genes Encoding ◽

Cyanobacterium Anabaena ◽

Anabaena Sp ◽

Pcc 7120

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Functional Diversity of TonB-Like Proteins in the Heterocyst-Forming Cyanobacterium Anabaena sp. PCC 7120

mSphere ◽

10.1128/msphere.00214-21 ◽

2021 ◽

Author(s):

Hannah Schätzle ◽

Sergio Arévalo ◽

Leonard Fresenborg ◽

Hans-Michael Seitz ◽

Enrique Flores ◽

...

Keyword(s):

Outer Membrane ◽

Functional Diversity ◽

Membrane Transporters ◽

Cyanobacterium Anabaena ◽

Anabaena Sp ◽

Tonb Protein ◽

Pcc 7120 ◽

Redundant Functions ◽

Outer Membrane Transporters

The genomes of many organisms encode more than one TonB protein, and their number does not necessarily correlate with that of TonB-dependent outer membrane transporters. Consequently, specific as well as redundant functions of the different TonB proteins have been identified.

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Identification of Streptococci to Species Level by Sequencing the Gene Encoding the Manganese-Dependent Superoxide Dismutase

Journal of Clinical Microbiology ◽

10.1128/jcm.36.1.41-47.1998 ◽

1998 ◽

Vol 36 (1) ◽

pp. 41-47 ◽

Cited By ~ 201

Author(s):

Claire Poyart ◽

Gilles Quesne ◽

Stephane Coulon ◽

Patrick Berche ◽

Patrick Trieu-Cuot

Keyword(s):

Superoxide Dismutase ◽

Pcr Assay ◽

Degenerate Primers ◽

Gene Encoding ◽

Genes Encoding ◽

Type Strains ◽

Internal Fragment ◽

Rrna Sequences ◽

16S Rrna Sequences

We have used a PCR assay based on the use of degenerate primers in order to characterize an internal fragment (sodAint ) representing approximately 85% of the genes encoding the manganese-dependent superoxide dismutase in various streptococcal type strains (S. acidominimus,S. agalactiae, S. alactolyticus, S. anginosus, S. bovis, S. constellatus,S. canis, S. cricetus, S. downei,S. dysgalactiae, S. equi subsp.equi, S. equi subsp. zooepidemicus,S. equinus, S. gordonii, S. iniae,S. intermedius, S. mitis, S. mutans, S. oralis, S. parasanguis,S. pneumoniae, S. porcinus, S. pyogenes, S. salivarius, S. sanguis,S. sobrinus, S. suis, S. thermophilus, and S. vestibularis). Phylogenetic analysis of these sodAint fragments yields an evolutionary tree having a topology similar to that of the tree constructed with the 16S rRNA sequences. We have shown that clinical isolates could be identified by determining the positions of theirsodAint fragments on the phylogenetic tree of the sodAint fragments of the type species. We propose this method for the characterization of strains that cannot be assigned to a species on the basis of their conventional phenotypic reactions.

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alr0117, a two-component histidine kinase gene, is involved in heterocyst development in Anabaena sp. PCC 7120

Microbiology ◽

10.1099/mic.0.26747-0 ◽

2004 ◽

Vol 150 (2) ◽

pp. 447-453 ◽

Cited By ~ 21

Author(s):

Degang Ning ◽

Xudong Xu

Keyword(s):

Histidine Kinase ◽

Regulatory System ◽

Gene Encoding ◽

Kinase Gene ◽

Two Component ◽

Two Component Signal Transduction ◽

Anabaena Sp ◽

Pcc 7120 ◽

Polysaccharide Layer ◽

Heterocyst Development

Anabaena sp. PCC 7120 was mutagenized by transposon Tn5-1087b, generating a mutant whose heterocysts lack the envelope polysaccharide layer. The transposon was located between nucleotides 342 and 343 of alr0117, a 918 bp gene encoding a histidine kinase for a two-component regulatory system. Complementation of the mutant with a DNA fragment containing alr0117 and targeted inactivation of the gene confirmed that alr0117 is involved in heterocyst development. RT-PCR showed that alr0117 was constitutively expressed in the presence or absence of a combined-nitrogen source. hepA and patB, the two genes turned on during wild-type heterocyst development, were no longer activated in an alr0117-null mutant. The two-component signal transduction system involving alr0117 may control the formation of the envelope polysaccharide layer and certain late events essential to the function of heterocysts.

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Construction and Characterization of Shuttle Vectors for Succinic Acid-Producing Rumen Bacteria

Applied and Environmental Microbiology ◽

10.1128/aem.01382-07 ◽

2007 ◽

Vol 73 (17) ◽

pp. 5411-5420 ◽

Cited By ~ 22

Author(s):

Yu-Sin Jang ◽

Young Ryul Jung ◽

Sang Yup Lee ◽

Ji Mahn Kim ◽

Jeong Wook Lee ◽

...

Keyword(s):

Succinic Acid ◽

Shuttle Vector ◽

Green Fluorescence Protein ◽

Expression Vectors ◽

Rumen Bacteria ◽

Gene Encoding ◽

Shuttle Vectors ◽

Genes Encoding ◽

Fluorescence Protein

ABSTRACT Shuttle vectors carrying the origins of replication that function in Escherichia coli and two capnophilic rumen bacteria, Mannheimia succiniciproducens and Actinobacillus succinogenes, were constructed. These vectors were found to be present at ca. 10 copies per cell. They were found to be stably maintained in rumen bacteria during the serial subcultures in the absence of antibiotic pressure for 216 generations. By optimizing the electroporation condition, the transformation efficiencies of 3.0 × 106 and 7.1 × 106 transformants/μg DNA were obtained with M. succiniciproducens and A. succinogenes, respectively. A 1.7-kb minimal replicon was identified that consists of the rep gene, four iterons, A+T-rich regions, and a dnaA box. It was found that the shuttle vector replicates via the theta mode, which was confirmed by sequence analysis and Southern hybridization. These shuttle vectors were found to be suitable as expression vectors as the homologous fumC gene encoding fumarase and the heterologous genes encoding green fluorescence protein and red fluorescence protein could be expressed successfully. Thus, the shuttle vectors developed in this study should be useful for genetic and metabolic engineering of succinic acid-producing rumen bacteria.

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Cloning and characterization of a 150 kDa microsphere antigen of Theileria parva that is immunologically cross-reactive with the polymorphic immunodominant molecule (PIM)

Parasitology ◽

10.1017/s0031182098003163 ◽

1998 ◽

Vol 117 (4) ◽

pp. 321-330 ◽

Cited By ~ 21

Author(s):

R. A. SKILTON ◽

R. P. BISHOP ◽

C. W. WELLS ◽

P. R. SPOONER ◽

E. GOBRIGHT ◽

...

Keyword(s):

Immunoelectron Microscopy ◽

Signal Sequence ◽

Peptide Sequence ◽

Theileria Parva ◽

Repeat Region ◽

Gene Encoding ◽

Genes Encoding ◽

Immunodominant Antigens ◽

Proline Rich Region

To identify the genes encoding novel immunodominant antigens of Theileria parva a λgt11 library of piroplasm genomic DNA was immunoscreened with bovine recovery serum and a gene encoding a 150 kDa antigen (p150) was identified. The predicted polypeptide contains an N-terminal secretory signal sequence and a proline-rich region of repeated amino acid motifs. The repeat region is polymorphic between stocks of T. parva in both copy number and sequence, and analysis of the repeat region from 10 stocks of T. parva revealed 5 p150 variants. A monoclonal antibody (mAb) against the T. parva polymorphic immunodominant molecule (PIM) cross-reacted with the recombinant p150. The p150 has sequence homology with a PIM peptide sequence containing the anti-PIM mAb epitope. Immunoelectron microscopy demonstrated that the p150 antigen, like PIM, is located in the microspheres of the sporozoites and is exocytosed following sporozoite invasion of the host lymphocyte. By immunoelectron microscopy p150 was subsequently transiently detectable on the sporozoite surface and in the lymphocyte cytosol. Immunoblotting showed that p150 is also expressed by the schizont stage, but at much lower levels compared to the sporozoite. These results suggest a major role for p150 in the early events of host–sporozoite interaction.

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