Making DNA without iron - induction of a manganese-dependent ribonucleotide reductase in response to iron starvation.


:Ribonucleotide reductases supply cells with their deoxyribonucleotides. Three enzyme types are known, classes I, II and III. Class II enzymes are anaerobic whereas class I enzymes are aerobic, and so class I and II enzymes are often produced by the same organism under opposing oxygen regimes. Escherichia coli contains two types of class I enzyme (Ia and Ib) with the Fe-dependent Ia enzyme (NrdAB) performing the major role aerobically, leaving the purpose of the Ib enzyme (NrdEF) unclear. Several papers have recently focused on the class Ib enzymes showing that they are Mn (rather than Fe) dependent and suggesting that the E. coli NrdEF may function under redox-stress conditions. A paper published in this issue of Molecular Microbiology from James Imlay's group confirms that this unexplained NrdEF Ib enzyme is Mn-dependent, but shows that it does not substitute for NrdAB during redox stress. Instead, a role during iron restriction is demonstrated. Thus, the purpose of NrdEF (and possibly other class Ib enzymes) is to enhance growth under aerobic, low-iron conditions, and to functionally replace the Fe-dependent NrdAB when iron is unavailable. This finding reveals a new mechanism by which bacteria adjust to life under iron deprivation.


Mol Microbiol


Molecular microbiology


Andrews SC




Has Abstract


2011-04-01 00:00:00












  • Reprogramming the infection mechanism of a filamentous phage.

    abstract::When they infect Escherichia coli cells, the filamentous phages IF1 and fd first interact with a pilus and then target TolA as their common receptor. They use the domains N2 and N1 of their gene-3-proteins (G3P) for these interactions but differ in the mechanism of infection. In G3P of phage IF1, N1 and N2 are indepen...

    journal_title:Molecular microbiology

    pub_type: 杂志文章


    authors: Lorenz SH,Schmid FX

    更新日期:2011-05-01 00:00:00

  • Biochemical characterization of Leishmania major aquaglyceroporin LmAQP1: possible role in volume regulation and osmotaxis.

    abstract::The Leishmania major aquaglyceroporin, LmAQP1, is responsible for the transport of trivalent metalloids, arsenite and antimonite. We have earlier shown that downregulation of LmAQP1 provides resistance to trivalent antimony compounds whereas increased expression of LmAQP1 in drug-resistant parasites can reverse the re...

    journal_title:Molecular microbiology

    pub_type: 杂志文章


    authors: Figarella K,Uzcategui NL,Zhou Y,LeFurgey A,Ouellette M,Bhattacharjee H,Mukhopadhyay R

    更新日期:2007-08-01 00:00:00

  • Quorum regulatory small RNAs repress type VI secretion in Vibrio cholerae.

    abstract::Type VI secretion is critical for Vibrio cholerae to successfully combat phagocytic eukaryotes and to survive in the presence of competing bacterial species. V. cholerae type VI secretion system genes are encoded in one large and two small clusters. In V. cholerae, type VI secretion is controlled by quorum sensing, th...

    journal_title:Molecular microbiology

    pub_type: 杂志文章


    authors: Shao Y,Bassler BL

    更新日期:2014-06-01 00:00:00

  • Mutagenesis, cloning and complementation analysis of C4-dicarboxylate transport genes from Rhodobacter capsulatus.

    abstract::Transposon mutagenesis was used to isolate insertion mutants of the photosynthetic bacterium Rhodobacter capsulatus which were unable to grow under aerobic conditions in the dark on malate, succinate or fumarate as sole carbon sources. Of five mutants isolated, all were deficient in C4-dicarboxylate transport. However...

    journal_title:Molecular microbiology

    pub_type: 杂志文章


    authors: Hamblin MJ,Shaw JG,Curson JP,Kelly DJ

    更新日期:1990-09-01 00:00:00

  • Mycobacterium smegmatis RNase J is a 5'-3' exo-/endoribonuclease and both RNase J and RNase E are involved in ribosomal RNA maturation.

    abstract::The presence of very different sets of enzymes, and in particular the presence of RNase E and RNase J, has been used to explain significant differences in RNA metabolism between the two model organisms Escherichia coli and Bacillus subtilis. However, these studies might have somewhat polarized our view of RNA metaboli...

    journal_title:Molecular microbiology

    pub_type: 杂志文章


    authors: Taverniti V,Forti F,Ghisotti D,Putzer H

    更新日期:2011-12-01 00:00:00

  • Proximal and distal sites bind LuxR independently and activate expression of the Vibrio harveyi lux operon.

    abstract::The LuxR regulatory protein of Vibrio harveyi as well as the autoinducer molecule, N-(3-hydroxybutanoyl) homoserine lactone, are known to be required for expression of luminescence. Although LuxR has been implicated in the activation of the promoter of the lux operon of V. harveyi, and can bind to two distinct sites u...

    journal_title:Molecular microbiology

    pub_type: 杂志文章


    authors: Miyamoto CM,Smith EE,Swartzman E,Cao JG,Graham AF,Meighen EA

    更新日期:1994-10-01 00:00:00

  • A single glutaredoxin or thioredoxin gene is essential for viability in the yeast Saccharomyces cerevisiae.

    abstract::Glutaredoxins and thioredoxins are small heat-stable oxidoreductases that have been conserved throughout evolution. The yeast Saccharomyces cerevisiae contains two gene pairs encoding cytoplasmic glutaredoxins (GRX1, GRX2) and thioredoxins (TRX1, TRX2). We report here that the quadruple trx1 trx2 grx1 grx2 mutant is i...

    journal_title:Molecular microbiology

    pub_type: 杂志文章


    authors: Draculic T,Dawes IW,Grant CM

    更新日期:2000-06-01 00:00:00

  • Aspergillus fumigatus mitochondrial electron transport chain mediates oxidative stress homeostasis, hypoxia responses and fungal pathogenesis.

    abstract::We previously observed that hypoxia is an important component of host microenvironments during pulmonary fungal infections. However, mechanisms of fungal growth in these in vivo hypoxic conditions are poorly understood. Here, we report that mitochondrial respiration is active in hypoxia (1% oxygen) and critical for fu...

    journal_title:Molecular microbiology

    pub_type: 杂志文章


    authors: Grahl N,Dinamarco TM,Willger SD,Goldman GH,Cramer RA

    更新日期:2012-04-01 00:00:00

  • An essential role for phoP in Mycobacterium tuberculosis virulence.

    abstract::Two-component regulatory proteins function in bacteria as sensory and adaptive factors in response to a wide range of environmental stimuli. Some two-component systems, such as PhoP/PhoQ, control transcription of key virulence genes essential for survival in host cells in diverse intracellular bacterial pathogens, inc...

    journal_title:Molecular microbiology

    pub_type: 杂志文章


    authors: Pérez E,Samper S,Bordas Y,Guilhot C,Gicquel B,Martín C

    更新日期:2001-07-01 00:00:00

  • Listeriolysin O: cholesterol inhibits cytolysis but not binding to cellular membranes.

    abstract::Listeriolysin O (LLO) binds to cholesterol-containing membranes in which it oligomerizes to form pores. Preincubation of the toxin with cholesterol is known to inhibit haemolysis, whereas the oxidized form of cholesterol has no inhibitory effect. Using immunoblot analyses and flow cytometry we demonstrate that preincu...

    journal_title:Molecular microbiology

    pub_type: 杂志文章


    authors: Jacobs T,Darji A,Frahm N,Rohde M,Wehland J,Chakraborty T,Weiss S

    更新日期:1998-06-01 00:00:00

  • Heterozygosity and functional allelic variation in the Candida albicans efflux pump genes CDR1 and CDR2.

    abstract::Elevated expression of the plasma membrane drug efflux pump proteins Cdr1p and Cdr2p was shown to accompany decreased azole susceptibility in Candida albicans clinical isolates. DNA sequence analysis revealed extensive allelic heterozygosity, particularly of CDR2. Cdr2p alleles showed different abilities to transport ...

    journal_title:Molecular microbiology

    pub_type: 杂志文章


    authors: Holmes AR,Tsao S,Ong SW,Lamping E,Niimi K,Monk BC,Niimi M,Kaneko A,Holland BR,Schmid J,Cannon RD

    更新日期:2006-10-01 00:00:00

  • Depletion of RNase HI activity in Escherichia coli lacking DNA topoisomerase I leads to defects in DNA supercoiling and segregation.

    abstract::Gyrase-mediated hypernegative supercoiling is one manifestation of R-loop formation, a phenomenon that is normally suppressed by topoisomerase I (topA) in Escherichia coli. Overproduction of RNase HI (rnhA), an enzyme that removes the RNA moiety of R-loops, prevents hypernegative supercoiling and allows growth of topA...

    journal_title:Molecular microbiology

    pub_type: 杂志文章


    authors: Usongo V,Nolent F,Sanscartier P,Tanguay C,Broccoli S,Baaklini I,Drlica K,Drolet M

    更新日期:2008-08-01 00:00:00

  • SaPI mutations affecting replication and transfer and enabling autonomous replication in the absence of helper phage.

    abstract::The SaPIs are chromosomal islands in staphylococci and other Gram-positive bacteria that carry genes for superantigens, virulence factors, resistance and certain metabolic functions. They have intimate relationships with certain temperate phages involving phage-induced excision, replication and efficient packaging in ...

    journal_title:Molecular microbiology

    pub_type: 杂志文章


    authors: Ubeda C,Maiques E,Barry P,Matthews A,Tormo MA,Lasa I,Novick RP,Penadés JR

    更新日期:2008-02-01 00:00:00

  • Domain switching and host recognition.

    abstract::The collective function of secreted pathogen effector molecules is to enhance the virulence and avirulence activity of the pathogen during the infection of its host. While the activity of a majority of pathogen effectors is unknown, several classes of effector molecules have been well characterized. Among these includ...

    journal_title:Molecular microbiology

    pub_type: 评论,杂志文章


    authors: Tian M,Day B

    更新日期:2006-09-01 00:00:00

  • Salmonella enterica serotype Typhimurium MisL is an intestinal colonization factor that binds fibronectin.

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    journal_title:Molecular microbiology

    pub_type: 杂志文章


    authors: Dorsey CW,Laarakker MC,Humphries AD,Weening EH,Bäumler AJ

    更新日期:2005-07-01 00:00:00

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    abstract::The gltX gene, encoding the glutamyl-tRNA synthetase (GluRS), and the valU operon, whose transcripts contain three tRNAVal/UAC and one tRNALys/UUU, are adjacent and divergently transcribed. It is the only known case of adjacent genes encoding an aminoacyl-tRNA synthetase and a tRNA precursor in Escherichia coli. The g...

    journal_title:Molecular microbiology

    pub_type: 杂志文章


    authors: Champagne N,Lapointe J

    更新日期:1998-03-01 00:00:00

  • Two binding proteins of the ABC transporter that confers growth of Bifidobacterium animalis subsp. lactis ATCC27673 on β-mannan possess distinct manno-oligosaccharide-binding profiles.

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    journal_title:Molecular microbiology

    pub_type: 杂志文章


    authors: Ejby M,Guskov A,Pichler MJ,Zanten GC,Schoof E,Saburi W,Slotboom DJ,Abou Hachem M

    更新日期:2019-07-01 00:00:00

  • The bacterial porin superfamily: sequence alignment and structure prediction.

    abstract::The porins of Gram-negative bacteria are responsible for the 'molecular sieve' properties of the outer membrane. They form large water-filled channels which allow the diffusion of hydrophilic molecules into the periplasmic space. Owing to the strong hydrophilicity of their amino acid sequence and the nature of their s...

    journal_title:Molecular microbiology

    pub_type: 杂志文章


    authors: Jeanteur D,Lakey JH,Pattus F

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  • Dermatan sulphate is released by proteinases of common pathogenic bacteria and inactivates antibacterial alpha-defensin.

    abstract::Defensins represent an evolutionarily conserved group of small peptides with potent antibacterial activities. We report here that extracellular proteinases secreted by the human pathogens Pseudomonas aeruginosa, Enterococcus faecalis and Streptococcus pyogenes release dermatan sulphate by degrading dermatan sulphate-c...

    journal_title:Molecular microbiology

    pub_type: 杂志文章


    authors: Schmidtchen A,Frick IM,Björck L

    更新日期:2001-02-01 00:00:00

  • The Brucella abortus Lon functions as a generalized stress response protease and is required for wild-type virulence in BALB/c mice.

    abstract::The gene encoding a Lon protease homologue has been cloned from Brucella abortus. The putative Brucella abortus Lon shares > 60% amino acid identity with its Escherichia coli counterpart and the recombinant form of this protein restores the capacity of an Escherichia coli lon mutant to resist killing by ultraviolet ir...

    journal_title:Molecular microbiology

    pub_type: 杂志文章


    authors: Robertson GT,Kovach ME,Allen CA,Ficht TA,Roop RM 2nd

    更新日期:2000-02-01 00:00:00

  • Differential regulation of antibiotic biosynthesis by DraR-K, a novel two-component system in Streptomyces coelicolor.

    abstract::A novel two-component system (TCS) designated as DraR-K (sco3063/sco3062) was identified to be involved in differential regulation of antibiotic biosynthesis in Streptomyces coelicolor. The S. coelicolor mutants with deletion of either or both of draR and draK exhibited significantly reduced actinorhodin (ACT) but inc...

    journal_title:Molecular microbiology

    pub_type: 杂志文章


    authors: Yu Z,Zhu H,Dang F,Zhang W,Qin Z,Yang S,Tan H,Lu Y,Jiang W

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  • The GATA factor AreA regulates localization and in vivo binding site occupancy of the nitrate activator NirA.

    abstract::The GATA factor AreA is a wide-domain regulator in Aspergillus nidulans with transcriptional activation and chromatin remodelling functions. AreA interacts with the nitrate-specific Zn(2)-C(6) cluster protein NirA and both proteins cooperate to synergistically activate nitrate-responsive genes. We have previously esta...

    journal_title:Molecular microbiology

    pub_type: 杂志文章


    authors: Berger H,Pachlinger R,Morozov I,Goller S,Narendja F,Caddick M,Strauss J

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  • An inner-membrane-associated virulence protein essential for T-DNA transfer from Agrobacterium tumefaciens to plants exhibits ATPase activity and similarities to conjugative transfer genes.

    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


    authors: Shirasu K,Koukolíková-Nicola Z,Hohn B,Kado CI

    更新日期:1994-02-01 00:00:00

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    journal_title:Molecular microbiology

    pub_type: 杂志文章


    authors: Seydel A,Gounon P,Pugsley AP

    更新日期:1999-11-01 00:00:00

  • cGMP homeostasis in malaria parasites-The key to perceiving and integrating environmental changes during transmission to the mosquito.

    abstract::Malaria-causing parasites are transmitted from humans to mosquitoes when developmentally arrested gametocytes are taken up by a female Anopheles during a blood meal. The changes in environment from human to mosquito activate gametogenesis, including a drop in temperature, a rise in pH, and a mosquito-derived molecule,...

    journal_title:Molecular microbiology

    pub_type: 杂志文章,评审


    authors: Brochet M,Balestra AC,Brusini L

    更新日期:2020-10-28 00:00:00

  • Differential Flo8p-dependent regulation of FLO1 and FLO11 for cell-cell and cell-substrate adherence of S. cerevisiae S288c.

    abstract::Cell-cell and cell-surface adherence represents initial steps in forming multicellular aggregates or in establishing cell-surface interactions. The commonly used Saccharomyces cerevisiae laboratory strain S288c carries a flo8 mutation, and is only able to express the flocculin-encoding genes FLO1 and FLO11, when FLO8 ...

    journal_title:Molecular microbiology

    pub_type: 杂志文章


    authors: Fichtner L,Schulze F,Braus GH

    更新日期:2007-12-01 00:00:00

  • Competitive activation of the Escherichia coli argO gene coding for an arginine exporter by the transcriptional regulators Lrp and ArgP.

    abstract::In vivo and in vitro analyses indicate that transcription of the argO gene coding for an arginine exporter is regulated by the global transcriptional regulator Lrp, an effect that went by unnoticed in previous genome-scale screenings of the Lrp regulatory network in Escherichia coli. Lrp activates the argO promoter fo...

    journal_title:Molecular microbiology

    pub_type: 杂志文章


    authors: Peeters E,Nguyen Le Minh P,Foulquié-Moreno M,Charlier D

    更新日期:2009-12-01 00:00:00

  • A recently isolated human commensal Escherichia coli ST10 clone member mediates enhanced thermotolerance and tetrathionate respiration on a P1 phage-derived IncY plasmid.

    abstract::The ubiquitous human commensal Escherichia coli has been well investigated through its model representative E. coli K-12. In this work, we initially characterized E. coli Fec10, a recently isolated human commensal strain of phylogroup A/sequence type ST10. Compared to E. coli K-12, the 4.88 Mbp Fec10 genome is charact...

    journal_title:Molecular microbiology

    pub_type: 杂志文章


    authors: Kamal SM,Cimdins-Ahne A,Lee C,Li F,Martín-Rodríguez AJ,Seferbekova Z,Afasizhev R,Wami HT,Katikaridis P,Meins L,Lünsdorf H,Dobrindt U,Mogk A,Römling U

    更新日期:2020-09-28 00:00:00

  • Interspecies sequence differences in the Mip protein from the genus Legionella: implications for function and evolutionary relatedness.

    abstract::The nucleotide sequence of the mip genes and their inferred amino acid sequences were determined from 35 Legionella species and compared with the published sequences for L. pneumophila, L. micdadei and L. longbeachae. The sequences were 69-97% conserved at the nucleotide level and 82-99% at the amino acid level, with ...

    journal_title:Molecular microbiology

    pub_type: 杂志文章


    authors: Ratcliff RM,Donnellan SC,Lanser JA,Manning PA,Heuzenroeder MW

    更新日期:1997-09-01 00:00:00

  • pH-regulated activation and release of a bacteria-associated phospholipase C during intracellular infection by Listeria monocytogenes.

    abstract::Listeria monocytogenes grows in the cytosol of mammalian cells and spreads from cell to cell without exiting the intracellular milieu. During cell-cell spread, bacteria become transiently entrapped in double-membrane vacuoles. Escape from these vacuoles is mediated in part by a bacterial phospholipase C (PC-PLC), whos...

    journal_title:Molecular microbiology

    pub_type: 杂志文章


    authors: Marquis H,Hager EJ

    更新日期:2000-01-01 00:00:00