Abstract:
:Caulobacter crescentus chromosome replication is precisely coupled to a developmental cell cycle. Like most eubacteria, C. crescentus has a DnaA homologue that is presumed to initiate chromosome replication. However, the C. crescentus replication origin (Cori) lacks perfect consensus Escherichia coli DnaA boxes. Instead, the Cori strong transcription promoter (Ps) may regulate chromosome replication through the CtrA cell cycle response regulator. We therefore created a conditional dnaA C. crescentus strain. Blocking dnaA expression immediately decreased DNA synthesis, which stopped after approximately one doubling period. Fluorescent flow cytometry confirmed that DNA synthesis is blocked at the initiation stage. Cell division also stopped, but not swarmer to stalked cell differentiation. All cells became stalked cells that grew as long filaments. Therefore, general transcription and protein synthesis continued, whereas DNA synthesis stopped. However, transcription was selectively blocked from the flagellar fliQ and fliL and methyltransferase ccrM promoters, which require CtrA and are blocked by different DNA synthesis inhibitors. Interestingly, transcription from Cori Ps continued unaltered. Therefore, Ps transcription is not sufficient for chromosome replication. Approximately 6-8 h after blocked dnaA expression, cells lost viability exponentially. Coincidentally, beta-galactosidase was induced from one transcription reporter, suggesting an altered physiology. We conclude that C. crescentus DnaA is essential for chromosome replication initiation, and perhaps also has a wider role in cell homeostasis.
journal_name
Mol Microbioljournal_title
Molecular microbiologyauthors
Gorbatyuk B,Marczynski GTdoi
10.1046/j.1365-2958.2001.02404.xsubject
Has Abstractpub_date
2001-04-01 00:00:00pages
485-97issue
2eissn
0950-382Xissn
1365-2958pii
mmi2404journal_volume
40pub_type
杂志文章abstract::The mechanistic details of the pathogenesis of Chlamydia, an obligate intracellular pathogen of global importance, have eluded scientists due to the scarcity of traditional molecular genetic tools to investigate this organism. Here we report a chemical biology strategy that has uncovered the first essential protease f...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/mmi.12306
更新日期:2013-08-01 00:00:00
abstract::The identification, isolation and characterization of a new Aspergillus nidulans positive-acting gene metR, which encodes a transcriptional activator of sulphur metabolism, is reported. metR mutants are tight auxotrophs requiring methionine or homocysteine for growth. Mutations in the metR gene are epistatic to mutati...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.2003.03617.x
更新日期:2003-08-01 00:00:00
abstract::A 2.7 kb fragment of Helicobacter pylori UA802 chromosomal DNA was cloned and sequenced. Three open reading frames (designated ORF1, ORF2 and ORF3, respectively) were predicted from the DNA sequence, of which ORF1 and ORF2 appeared to be located within the same operon. The deduced 611-amino-acid sequence of ORF1, a P-...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1995.tb02224.x
更新日期:1995-01-01 00:00:00
abstract::The Leishmania major aquaglyceroporin, LmAQP1, is responsible for the transport of antimonite [Sb(III)], an activated form of Pentostam or Glucantime. Downregulation of LmAQP1 provides resistance to trivalent antimony compounds and increased expression of LmAQP1 in drug-resistant parasites can reverse the resistance. ...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2008.06494.x
更新日期:2008-12-01 00:00:00
abstract::Capsular polysaccharides are well-established virulence factors of pathogenic bacteria. Their biosynthesis and export are regulated within the transmembrane polysaccharide assembly machinery by the autophosphorylation of atypical tyrosine-kinases, named BY-kinases. However, the accurate functioning of these tyrosine-k...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2010.07291.x
更新日期:2010-09-01 00:00:00
abstract::The dominant, polA1-independent replicon of pGSH500, rep beta (1.8 kb), consists of a cis-acting oriV region of 245 bp; a repB gene that is essential for autonomous replication and 18, 30 to 36 bp iterons which constitute the inc/cop region. The molecular organization of rep beta resembles that of mini-pCU1 (IncN). Fu...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1993.tb01171.x
更新日期:1993-03-01 00:00:00
abstract::The effect of the unc transcription terminator on expression of uncC, encoding the epsilon subunit of Escherichia coli F1-ATPase, from plasmids was studied. The cloned sequence in pTK1 included the uncC ribosome binding site, the uncC structural gene, and the unc transcription terminator. The cloned region in pSD37 wa...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1990.tb02043.x
更新日期:1990-11-01 00:00:00
abstract::Fourteen Rhodobacter capsulatus mutants unable to grow with xanthine as sole nitrogen source were isolated by random Tn5 mutagenesis. Five of these Tn5 insertions were mapped within two adjacent chromosomal EcoRI fragments hybridizing to oligonucleotides synthesized according to conserved amino acid sequences of eukar...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.1998.00733.x
更新日期:1998-02-01 00:00:00
abstract::Borrelia hermsii, an agent of relapsing fever, avoids the host's immune response by means of multiphasic antigenic variation. Serotype specificity is determined by variable antigens called the Vmp lipoproteins. Through recombination between linear plasmids a formerly silent vmp gene replaces another vmp gene at a telo...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1991.tb02132.x
更新日期:1991-02-01 00:00:00
abstract::In cyanobacteria and chloroplasts, exposure to HL damages the photosynthetic apparatus, especially the D1 subunit of Photosystem II. To avoid chronic photoinhibition, a PSII repair cycle operates to replace damaged PSII subunits with newly synthesised versions. To determine the sub-cellular location of this process, w...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/mmi.12940
更新日期:2015-05-01 00:00:00
abstract::Plasmodium falciparum erythrocyte membrane protein-1 (PfEMP-1) is exposed on the surface of infected erythrocytes where it both acts as an important pathogenicity factor in malaria and undergoes antigenic variation as a means of immune evasion. Because the mammalian erythrocyte lacks a protein secretory machinery ther...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2004.04468.x
更新日期:2005-02-01 00:00:00
abstract::In enteric bacteria, proteins of the Hha/YmoA family play a role in the regulation of gene expression in response to environmental factors. Interaction of both Hha and YmoA with H-NS has been reported, and an Hha/H-NS complex has been shown to modulate expression in Escherichia coli of the haemolysin operon of plasmid...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2004.04268.x
更新日期:2004-10-01 00:00:00
abstract::Iron-sulfur (Fe-S) clusters are prosthetic groups on proteins that function in a range of enzymatic and electron transfer reactions. Fe-S cluster synthesis is essential for the survival of all eukaryotes. Independent Fe-S cluster biosynthesis pathways occur in the mitochondrion, plastid, and cytosolic compartments of ...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/mmi.14651
更新日期:2020-11-22 00:00:00
abstract::In the multicellular bacterium Streptomyces coelicolor, functions of developmental (bald) genes are required for the biosynthesis of SapB, a hydrophobic peptidic morphogen that facilitates aerial hyphae formation. Here, we show that aerial hyphal growth and SapB biosynthesis could be activated independently from the n...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.2002.03255.x
更新日期:2002-12-01 00:00:00
abstract::Bacterial cytokinesis is orchestrated by an assembly of essential cell division proteins that form a supramolecular structure known as the divisome. DivIB and its orthologue FtsQ are essential members of the divisome in Gram-positive and Gram-negative bacteria respectively. DivIB is a bitopic membrane protein composed...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2008.06114.x
更新日期:2008-03-01 00:00:00
abstract::Biosynthesis of fatty acids is one of the most fundamental biochemical pathways in nature. In bacteria and plant chloroplasts, the committed and rate-limiting step in fatty acid biosynthesis is catalyzed by a multi-subunit form of the acetyl-CoA carboxylase enzyme (ACC). This enzyme carboxylates acetyl-CoA to produce ...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/mmi.12912
更新日期:2015-03-01 00:00:00
abstract::Beta-oxidation (beta-ox) occurs exclusively in the peroxisomes of Saccharomyces cerevisiae and other yeasts, leading to the supposition that fungi lack mitochondrial beta-ox. Here we present unequivocal evidence that the filamentous fungus Aspergillus nidulans houses both peroxisomal and mitochondrial beta-ox. While g...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2004.04340.x
更新日期:2004-12-01 00:00:00
abstract::Plasmodium vivax is one of four Plasmodium species that cause human malaria. P. vivax and a related simian malaria parasite, Plasmodium knowlesi, invade erythrocytes by binding the Duffy antigen/receptor for chemokines (DARC) through their respective Duffy binding proteins. Here we show that tyrosines 30 and 41 of DAR...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2004.04478.x
更新日期:2005-03-01 00:00:00
abstract::We have shown previously that some particular mutations in bacteriophage Mu repressor, the frameshift vir mutations, made the protein very sensitive to the Escherichia coli ATP-dependent Clp protease. This enzyme is formed by the association between a protease subunit (ClpP) and an ATPase subunit. ClpA, the best chara...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1994.tb00387.x
更新日期:1994-03-01 00:00:00
abstract::We have characterized a series of amber mutations in the A gene of bacteriophage Mu encoding the phage transposase. We tested different activities of these mutant proteins either in a sup0 strain or in different sup bacteria. In conjunction with the results described in the accompanying paper by Bétermier et al. (1989...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1989.tb00265.x
更新日期:1989-09-01 00:00:00
abstract::The expression of the structural genes for lysine (LYS) biosynthesis is controlled by a pathway-specific regulation mediated by the transcriptional activator Lys14 in the presence of alpha-aminoadipate semialdehyde, an intermediate of the pathway acting as a co-inducer. Owing to end product inhibition of the first ste...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.1998.00916.x
更新日期:1998-07-01 00:00:00
abstract::Cell wall lipids of Mycobacterium tuberculosis containing multiple methylbranched fatty acids play critical roles in pathogenesis and thus offer targets for new antimycobacterial drugs. Mycocerosicacid synthase gene (mas) encodes the enzyme that produces one class of such acids. Seven mas-like genes (msls) were identi...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.2002.03119.x
更新日期:2002-09-01 00:00:00
abstract::Cholesterol catabolism is widespread in actinobacteria and is critical for Mycobacterium tuberculosis (Mtb) virulence. Catabolism of steroid nucleus rings C and D is poorly understood: it is initiated by the CoA thioesterification of 3aα-H-4α(3'-propanoate)-7aβ-methylhexahydro-1,5-indanedione (HIP) by FadD3, whose gen...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/mmi.12340
更新日期:2013-09-01 00:00:00
abstract::Roughly 10% of all genes in Escherichia coli are controlled by the global transcription factor Lrp, which responds to nutrient availability. Bioinformatically, we identified lrp as one of several putative targets for the sRNA MicF, which is transcriptionally downregulated by Lrp. Deleting micF results in higher Lrp le...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2012.07994.x
更新日期:2012-05-01 00:00:00
abstract::Histidine kinases (HK) sense and transduce via phosphorylation events many intra- and extracellular signals in bacteria, archaea, slime moulds and plants. HK are also widespread in the fungal kingdom, but their precise roles in the regulation of physiological processes remain largely obscure. Expanding genomic resourc...
journal_title:Molecular microbiology
pub_type: 杂志文章,评审
doi:10.1111/mmi.12911
更新日期:2015-03-01 00:00:00
abstract::A respiratory quinol oxidase complex that is encoded by the soxABCD operon has been purified from the thermoacidophilic archaeon Sulfolobus acidocaldarius. The enzyme was solubilized with dodecyl maltoside and purified in the presence of this detergent and ethylene glycol. The complex is hydrodynamically homogeneous a...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1994.tb00426.x
更新日期:1994-07-01 00:00:00
abstract::Folate metabolism in malaria parasites is a long-standing, clinical target for chemotherapy and prophylaxis. However, despite determination of the complete genome sequence of the lethal species Plasmodium falciparum, the pathway of de novo folate biosynthesis remains incomplete, as no candidate gene for dihydroneopter...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2007.06073.x
更新日期:2008-02-01 00:00:00
abstract::Red cell invasion by Plasmodium merozoites involves multiple steps such as attachment, apical reorientation, junction formation and entry into a parasitophorous vacuole. These steps are mediated by specific molecular interactions. P. vivax and the simian parasite P. knowlesi require interaction with the Duffy blood gr...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2005.04523.x
更新日期:2005-03-01 00:00:00
abstract::The majority of characterized bacterial dipeptide permeases (Dpp) are membrane-associated complexes of five proteins belonging to the ABC-transporter family. They have been found to be involved in the uptake of essential amino acids, haem production, chemotaxis and sporulation. A 5.8 kb genomic DNA fragment of the ser...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.1998.00898.x
更新日期:1998-06-01 00:00:00
abstract::Enhancement of enzyme thermostability by protein engineering gives us information about the thermostabilization mechanism as well as advantages for industrial use of enzymes. In this study, we enhanced the thermostability of endoglucanase EngB, one component of the cellulase complex (cellulosome) from Clostridium cell...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.2002.03049.x
更新日期:2002-08-01 00:00:00