Abstract:
:The six biochemical steps of the de novo pyrimidine biosynthesis pathway are conserved in all known organisms. However, in animals and fungi, unlike prokaryotes, at least the first two activities are grouped on a multifunctional enzyme. Here, we report cloning, mapping and transcriptional characterization of some pyrimidine biosynthesis genes in the filamentous fungus Aspergillus nidulans. The first two steps of the pathway are performed by a multifunctional enzyme comprising the activities of carbamoyl phosphate synthetase (CPSase) and aspartate transcarbamylase (ATCase). This polypeptide is encoded by a 7 kbp cluster gene, pyrABCN, which has a high degree of nucleotide identity with the Ura2 gene in Saccharomyces cerevisiae. The enzyme of the third step, dihydroorotase (DHOase), is encoded by a separate locus, pyrD. However, the pyrABCN gene apparently contains an evolutionary remnant of a DHOase-encoding sequence, similarly to the Ura2 gene of Saccharomyces cerevisiae. The pyrABCN gene is transcribed as a single 7 kb mRNA species. The level of transcripts of pyrABCN, pyrD and, to a lesser degree, pyrF genes responds to the presence of exogenous pyrimidines and to the conditions of pyrimidine starvation. Derepression of pyrABCN and pyrD under pyrimidine starvation is noticeably enhanced in pyrE mutants that accumulate dihydroorotic acid. The pyrABCN gene maps to the distal portion of the right arm of the chromosome VIII, whereas the pyrD gene, in contrast to early genetic data, is closely linked to the brlA gene and located to the right of it. Our data on mitotic recombination should help to verify the genetic map of the chromosome VIII. Comparison of amino acid sequences of active dihydroorotases with related enzymes and with their non-functional homologues in yeast and Aspergillus indicates that the active dihydroorotases from fungi are more similar to ureases and enzymes of the pyrimidine degradation pathway. The 'silent' dihydroorotase domains of the multifunctional enzymes from fungi and active DHOase domains of the multifunctional enzymes in higher eukaryotes are more closely related to bacterial dehydroorotases.
journal_name
Mol Microbioljournal_title
Molecular microbiologyauthors
Aleksenko A,Liu W,Gojkovic Z,Nielsen J,Piskur Jdoi
10.1046/j.1365-2958.1999.01507.xsubject
Has Abstractpub_date
1999-08-01 00:00:00pages
599-611issue
3eissn
0950-382Xissn
1365-2958pii
mole1507journal_volume
33pub_type
杂志文章abstract::The archaeal transcription apparatus is chimeric: its core components (RNA polymerase and basal factors) closely resemble those of eukaryotic RNA polymerase II, but the putative archaeal transcriptional regulators are overwhelmingly of bacterial type. Particular interest attaches to how these bacterial-type effectors,...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2005.04563.x
更新日期:2005-05-01 00:00:00
abstract::pAM beta 1 is a low-copy-number, promiscuous plasmid from Gram-positive bacteria that replicates by a unidirectional theta-type mode. Its replication is initiated by an original mechanism, involving the positive rate-limiting RepE protein. Here we show that the pAM beta 1-encoded CopF protein is involved in negative r...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1994.tb02181.x
更新日期:1994-11-01 00:00:00
abstract::The F factor traY gene product (TraYp) is a site-specific DNA-binding protein involved in initiation of DNA transfer during bacterial conjugation. The sequence of TraYp exhibits a unique direct-repeat structure predicted to have a ribbon-helix-helix DNA-binding motif in each repeat unit. The stoichiometry of TraYp bin...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1996.tb02638.x
更新日期:1996-06-01 00:00:00
abstract::ToxR of Vibrio cholerae directly activates the ompU promoter, but requires a second activator, TcpP to activate the toxT promoter. ompU encodes a porin, while toxT encodes the transcription factor, ToxT, which activates V. cholerae virulence genes including cholera toxin and the toxin co-regulated pilus. Using an ompU...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2011.07681.x
更新日期:2011-07-01 00:00:00
abstract::The Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family of antigenically diverse proteins is expressed on the surface of human erythrocytes infected with the malaria parasite P. falciparum, and mediates cytoadherence to the host vascular endothelium. In this report, we show that export of PfEMP1 is sl...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.2003.03784.x
更新日期:2003-11-01 00:00:00
abstract::Phosphorylcholine (ChoP) is a common surface feature of many mucosal organisms, including Neisseria spp., in which it is present exclusively on pili of pathogenic Neisseria and on the lipopolysaccharide (LPS) of commensal Neisseria (Cn). Its presence in Cn has been confirmed by nuclear magnetic resonance. It appears t...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.2002.02755.x
更新日期:2002-01-01 00:00:00
abstract::We studied superoxide dismutases (SODs) in the encapsulated yeast Cryptococcus neoformans (Cn) variety gattii to analyse the role of mitochondrial MnSOD (SOD2) in fungal biology and virulence. SOD2 was cloned from a Cn cosmid library, sod2 mutant and sod2 + SOD2 reconstituted strains were constructed by homologous rec...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2005.04503.x
更新日期:2005-03-01 00:00:00
abstract::Overexpression of the MDR1 gene, encoding a multi-drug efflux pump of the major facilitator superfamily, is a major cause of resistance to the widely used antifungal agent fluconazole and other toxic substances in the fungal pathogen Candida albicans. We found that all tested clinical and in vitro generated C. albican...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2008.06309.x
更新日期:2008-08-01 00:00:00
abstract::In general, wild Escherichia coli strains can grow effectively under moderately acidic organic acid-rich conditions. We found that the Shiga Toxin-producing E. coli (STEC) O157:H7 NGY9 grows more quickly than a K-12 strain in Luria-Bertani (LB)-2-morpholinoethanesulphonic acid (MES) broth supplemented with acetic acid...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.2002.02768.x
更新日期:2002-02-01 00:00:00
abstract::The kilB locus (which is unclonable in the absence of korB) of broad-host-range plasmid RK2 (60 kb) lies between the trfA operon (co-ordinates 16.4 to 18.2 kb), which encodes a protein essential for vegetative replication, and the Tra2 block of conjugative transfer genes (co-ordinates 20.0 to 27.0 kb). Promoter probe ...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1992.tb01541.x
更新日期:1992-04-01 00:00:00
abstract::The AMA1 sequence is an efficient plasmid replicator and transformation enhancer in Aspergillus nidulans. It comprises two long perfect inverted repeats (MATE elements) flanking a short, unique, central spacer. Subclone analysis indicates that the complete inverted duplication, but not the unique central spacer, is ne...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1996.tb02629.x
更新日期:1996-04-01 00:00:00
abstract::Ethylenediaminetetraacetate (EDTA) is currently the most abundant organic pollutant due to its recalcitrance and extensive use. Only a few bacteria can degrade it, using EDTA monooxygenase (EmoA) to initiate the degradation. EmoA is an FMNH2 -dependent monooxygenase that requires an NADH:FMN oxidoreductase (EmoB) to p...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/mmi.13363
更新日期:2016-06-01 00:00:00
abstract::Mechanisms of hydrogen peroxide generation in Escherichia coli were investigated using a strain lacking scavenging enzymes. Surprisingly, the deletion of many abundant flavoenzymes that are known to autoxidize in vitro did not substantially lessen overall H(2)O(2) formation. However, H(2)O(2) production diminished by ...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2010.07059.x
更新日期:2010-03-01 00:00:00
abstract::N15 is a bacteriophage of Escherichia coli that resembles lambda, but, unlike lambda, it lysogenizes as a linear plasmid. We show that stable maintenance of this unusual plasmid-prophage depends on the parA and parB genes, relatives of the partition genes of F and P1 plasmids. ParB of N15, like its F- and P1-encoded h...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.2001.02632.x
更新日期:2001-10-01 00:00:00
abstract::Candida albicans is an opportunistic yeast that can cause life-threatening systemic infection in immunocompromised individuals. During infections, C. albicans has to cope with genotoxic stresses generated by the host immune system. DNA-protein crosslink (DPC), the covalent linkage of proteins with DNA, is one type of ...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/mmi.14518
更新日期:2020-09-01 00:00:00
abstract::Regulation of DNA replication in Bacillus subtilis involves a post-initiation mechanism which is subject to control by the Stringent System, an essential regulatory network, mediated by the alarmone, ppGpp. In detailed studies using DNA-DNA hybridization procedures, we have now shown that, following the induction of t...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1995.tb02243.x
更新日期:1995-01-01 00:00:00
abstract::The osteolytic toxin of Pasteurella multocida induces bone resorption in vivo and in vitro (Foged et al., 1988; Kimman et al., 1987). In this report the toxin-encoding toxA gene is sequenced, and the deduced primary structure of the toxin shows a protein of 1285 amino acids, containing a striking homology to a metal-b...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.1990.tb00652.x
更新日期:1990-05-01 00:00:00
abstract::Among players in neurobiology, ion channels are the demigods that underlie all our senses, behaviour and intelligence. In animals, these 'gated pores' detect ligands, voltage, heat or stretch forces and emit electric or ionic signals. Patch clamp and genome sequencing now show that nearly all microbes also have these ...
journal_title:Molecular microbiology
pub_type: 杂志文章,评审
doi:10.1111/j.1365-2958.2004.04180.x
更新日期:2004-07-01 00:00:00
abstract::Alternative oxidase (AOX) is a respiratory oxidase found in certain eukaryotes and bacteria; however, its role in bacterial physiology is unclear. Exploiting the genetic tractability of the bacterium Vibrio fischeri, we explore the regulation of aox expression and AOX function. Using quantitative PCR and reporter assa...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2010.07194.x
更新日期:2010-07-01 00:00:00
abstract::Helicobacter pylori is anomalous among non nitrogen-fixing bacteria in containing an incomplete NIF system for Fe-S cluster assembly comprising two essential proteins, NifS (cysteine desulfurase) and NifU (scaffold protein). Although nifU deletion strains cannot be obtained via the conventional gene replacement, a Nif...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/mmi.13942
更新日期:2018-05-01 00:00:00
abstract::Prior studies have shown that the catalase-deficient pathogen Streptococcus pyogenes (group A streptococcus) has a robust ability to resist oxidative stress that partially involves the transcriptional regulator PerR. However, the extent of the PerR regulon and the contribution of the members of this regulon to virulen...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2004.04370.x
更新日期:2005-01-01 00:00:00
abstract::IscU is a central component of the ISC machinery and serves as a scaffold for de novo assembly of Fe-S clusters. The dedicated chaperone system composed of the Hsp70-chaperone HscA and the J-protein cochaperone HscB synergistically interacts with IscU and facilitates cluster transfer from IscU to recipient apo-protein...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/mmi.14646
更新日期:2020-11-17 00:00:00
abstract::Escherichia coli FtsN is a bitopic membrane protein that is essential for triggering active cell constriction. A small periplasmic subdomain ((E) FtsN) is required and sufficient for function, but its mechanism of action is unclear. We isolated extragenic (E) FtsN*-suppressing mutations that restore division in cells ...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/mmi.12906
更新日期:2015-03-01 00:00:00
abstract::Toxin-antitoxin (TA) systems on the chromosomes of free-living bacteria appear to facilitate cell survival during intervals of stress by inducing a state of reversible growth arrest. However, upon prolonged stress, TA toxin action leads to cell death. They have been implicated in several clinically important phenomena...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2008.06572.x
更新日期:2009-03-01 00:00:00
abstract::Replication origins of a family of bacterial plasmids have multiple sites, called iterons, for binding a plasmid-specific replication initiator protein. The iteron-initiator interactions are essential for plasmid replication as well as for inhibition of plasmid over-replication. The inhibition increases with plasmid c...
journal_title:Molecular microbiology
pub_type: 杂志文章,评审
doi:10.1046/j.1365-2958.2000.01986.x
更新日期:2000-08-01 00:00:00
abstract::Of the four Plasmodium species that routinely cause malaria in humans, Plasmodium falciparum is responsible for the majority of malaria mortality and consequently gets most of the headlines. Outside Africa, however, more malaria cases are caused by its distant cousin Plasmodium vivax, resulting in a daunting morbidity...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2005.04518.x
更新日期:2005-03-01 00:00:00
abstract:SUMMARY:The conserved bacterial protein RloC, a distant homologue of the tRNA(Lys) anticodon nuclease (ACNase) PrrC, is shown here to act as a wobble nucleotide-excising and Zn(++)-responsive tRNase. The more familiar PrrC is silenced by a genetically linked type I DNA restriction-modification (R-M) enzyme, activated b...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2008.06387.x
更新日期:2008-09-01 00:00:00
abstract::Photorhabdus and Xenorhabdus bacteria colonize the intestines of the infective soil-dwelling stage of entomophagous nematodes, Heterorhabditis and Steinernema, respectively. These nematodes infect susceptible insect larvae and release the bacteria into the insect blood. The bacteria kill the insect larvae and convert ...
journal_title:Molecular microbiology
pub_type: 杂志文章,评审
doi:10.1111/j.1365-2958.2007.05671.x
更新日期:2007-04-01 00:00:00
abstract::Meningococcal gdhA, encoding the NADP-specific l-glutamate dehydrogenase (NADP-GDH), is essential for systemic infection in an infant rat model. In this paper, a limited transcriptional analysis detected differences in gdhA expression among clinical isolates. In strains expressing high levels of gdhA mRNA, two promote...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1111/j.1365-2958.2003.03947.x
更新日期:2004-03-01 00:00:00
abstract::We have cloned, characterized and inactivated genes encoding putative UspA paralogues in Escherichia coli. The yecG (uspC), yiiT (uspD) and ydaA (uspE) genes were demonstrated to encode protein pro-ducts and these were mapped to spots in the E. coli proteomic database. Expression analysis using chromosomal transcripti...
journal_title:Molecular microbiology
pub_type: 杂志文章
doi:10.1046/j.1365-2958.2002.02720.x
更新日期:2002-01-01 00:00:00