scholarly journals Multicopy plasmid integration in Komagataella phaffii mediated by a defective auxotrophic marker

2017 ◽  
Vol 16 (1) ◽  
Author(s):  
Maritza Ocampo Betancur ◽  
Viviane Castelo Branco Reis ◽  
André Moraes Nicola ◽  
Janice Lisboa De Marco ◽  
Lídia Maria Pepe de Moraes ◽  
...  
Keyword(s):  
Multicopy Plasmid ◽  
Plasmid Integration ◽  
Komagataella Phaffii ◽  
Auxotrophic Marker

scholarly journals Active and inactive transplacement of the M26 recombination hotspot in Schizosaccharomyces pombe.

Genetics ◽  
1995 ◽  
Vol 141 (1) ◽  
pp. 33-48
Author(s):  
J B Virgin ◽  
J Metzger ◽  
G R Smith
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Meiotic Recombination ◽  
Plasmid Dna ◽  
Context Effect ◽  
Intragenic Recombination ◽  
Multicopy Plasmid ◽  
Chromosomal Locus ◽  
Sequence Element ◽  
Recombination Hotspot ◽  
Recombination Hotspots

Abstract The ade6-M26 mutation of the fission yeast Schizosaccharomyces pombe creates a meiotic recombination hotspot that elevates ade6 intragenic recombination approximately 10-15-fold. A heptanucleotide sequence including the M26 point mutation is required but not sufficient for hotspot activity. We studied the effects of plasmid and chromosomal context on M26 hotspot activity. The M26 hotspot was inactive on a multicopy plasmid containing M26 embedded within 3.0 or 5.9 kb of ade6 DNA. Random S. pombe genomic fragments totaling approximately 7 Mb did not activate the M26 hotspot on a plasmid. M26 hotspot activity was maintained when 3.0-, 4.4-, and 5.9-kb ade6-M26 DNA fragments, with various amounts of non-S. pombe plasmid DNA, were integrated at the ura4 chromosomal locus, but only in certain configurations relative to the ura4 gene and the cointegrated plasmid DNA. Several integrations created new M26-independent recombination hotspots. In all cases the non-ade6 DNA was located > 1 kb from the M26 site, and in some cases > 2 kb. Because the chromosomal context effect was transmitted over large distances, and did not appear to be mediated by a single discrete DNA sequence element, we infer that the local chromatin structure has a pronounced effect on M26 hotspot activity.

Inactivation or amplification of the spa2 gene, encoding a potential stationary-phase regulator, affects differentiation in Streptomyces ambofaciens

1997 ◽  
Vol 43 (12) ◽  
pp. 1118-1125 ◽  
Author(s):  
Martine Aubert ◽  
Elisabeth Weber ◽  
Brigitte Gintz ◽  
Bernard Decaris ◽  
Keith F. Chater
Keyword(s):  
Stationary Phase ◽  
Antibiotic Production ◽  
Morphological Differentiation ◽  
Aerial Mycelium ◽  
Detectable Effect ◽  
Multicopy Plasmid ◽  
Gene Encoding ◽  
Wild Type Phenotype ◽  
Streptomyces Ambofaciens ◽  
Mycelial Development

The deduced product of the spa2 gene of Streptomyces ambofaciens is a homologue of RspA, involved in stationary-phase σs factor regulation in Escherichia coli. This suggests that Spa2 could play a part in stationary-phase-associated differentiation in S. ambofaciens. The disruption of spa2 led to reductions in aerial mycelial development and associated spore pigmentation. The mutant phenotype reverted to the wild-type phenotype when the disruption construct spontaneously excised. The spa2 disruption had no detectable effect on growth rates in different media or antibiotic production and resistance. When spa2 was placed on a multicopy plasmid, a severe defect in formation and pigmentation of aerial mycelium resulted. These results strongly suggest that Spa2 is involved in a complex manner in the morphological differentiation process.Key words: Streptomyces, differentiation, stationary-phase regulator.

scholarly journals Yeast NOP2 encodes an essential nucleolar protein with homology to a human proliferation marker.

1994 ◽  
Vol 127 (6) ◽  
pp. 1799-1813 ◽  
Author(s):  
E de Beus ◽  
J S Brockenbrough ◽  
B Hong ◽  
J P Aris
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Ribosomal Protein ◽  
Nucleolar Protein ◽  
Mrna Levels ◽  
Multicopy Plasmid ◽  
Yeast Saccharomyces Cerevisiae ◽  
Protein Levels ◽  
Significant Amino Acid Sequence ◽  
Ribosomal Protein L3

We have isolated a gene (NOP2) encoding a nucleolar protein during a search for previously unidentified nuclear proteins in the yeast Saccharomyces cerevisiae. The protein encoded by NOP2 (Nop2p) has a predicted molecular mass of 70 kD, migrates at 90 kD by SDS-PAGE, and is essential for cell viability. Nop2p shows significant amino acid sequence homology to a human proliferation-associated nucleolar protein, p120. Approximately half of Nop2p exhibits 67% amino acid sequence identity to p120. Analysis of subcellular fractions indicates that Nop2p is located primarily in the nucleus, and nuclear fractionation studies suggest that Nop2p is associated with the nucleolus. Indirect immunofluorescence localization of Nop2p shows a nucleolar-staining pattern, which is heterogeneous in appearance, and a faint staining of the cytoplasm. The expression of NOP2 during the transition from stationary phase growth arrest to rapid growth was measured, and compared to the expression of TCM1, which encodes the ribosomal protein L3. Nop2p protein levels are markedly upregulated during the onset of growth, compared to the levels of ribosomal protein L3, which remain relatively constant. NOP2 mRNA levels also increase during the onset of growth, accompanied by a similar increase in the levels of TCM1 mRNA. The consequences of overexpressing NOP2 from the GAL10 promoter on a multicopy plasmid were investigated. Although NOP2 overexpression produced no discernible growth phenotype and had no effect on ribosome subunit synthesis, overexpression was found to influence the morphology of the nucleolus, as judged by electron microscopy. Overexpression caused the nucleolus to become detached from the nuclear envelope and to become more rounded and/or fragmented in appearance. These findings suggest roles for NOP2 in nucleolar function during the onset of growth, and in the maintenance of nucleolar structure.

scholarly journals A Recombination Repair Gene of Schizosaccharomyces pombe, rhp57, Is a Functional Homolog of the Saccharomyces cerevisiae RAD57 Gene and Is Phylogenetically Related to the Human XRCC3 Gene

Genetics ◽  
2000 ◽  
Vol 154 (4) ◽  
pp. 1451-1461 ◽  
Author(s):  
Yasuhiro Tsutsui ◽  
Takashi Morishita ◽  
Hiroshi Iwasaki ◽  
Hiroyuki Toh ◽  
Hideo Shinagawa
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Schizosaccharomyces Pombe ◽  
Genomic Library ◽  
Synthetic Lethality ◽  
Multicopy Plasmid ◽  
Repair Gene ◽  
Recombination Repair ◽  
Xrcc3 Gene ◽  
Γ Rays ◽  
Lower Temperature

Abstract To identify Schizosaccharomyces pombe genes involved in recombination repair, we identified seven mutants that were hypersensitive to both methyl methanesulfonate (MMS) and γ-rays and that contained mutations that caused synthetic lethality when combined with a rad2 mutation. One of the mutants was used to clone the corresponding gene from a genomic library by complementation of the MMS-sensitive phenotype. The gene obtained encodes a protein of 354 amino acids whose sequence is 32% identical to that of the Rad57 protein of Saccharomyces cerevisiae. An rhp57 (RAD57 homolog of S. pombe) deletion strain was more sensitive to MMS, UV, and γ-rays than the wild-type strain and showed a reduction in the frequency of mitotic homologous recombination. The MMS sensitivity was more severe at lower temperature and was suppressed by the presence of a multicopy plasmid bearing the rhp51 gene. An rhp51 rhp57 double mutant was as sensitive to UV and γ-rays as an rhp51 single mutant, indicating that rhp51 function is epistatic to that of rhp57. These characteristics of the rhp57 mutants are very similar to those of S. cerevisiae rad57 mutants. Phylogenetic analysis suggests that Rhp57 and Rad57 are evolutionarily closest to human Xrcc3 of the RecA/Rad51 family of proteins.

scholarly journals Amplification of the Tetracycline Resistance Determinant of pAMα1 in Enterococcus faecalis Requires a Site-Specific Recombination Event Involving Relaxase

2002 ◽  
Vol 184 (18) ◽  
pp. 5187-5193 ◽  
Author(s):  
M. Victoria Francia ◽  
Don B. Clewell
Keyword(s):  
Enterococcus Faecalis ◽  
Recombination Event ◽  
Tandem Repeats ◽  
Tetracycline Resistance ◽  
Multicopy Plasmid ◽  
Site Specific ◽  
Site Specific Recombination ◽  
Rate Limiting Step ◽  
A Site ◽  
Rate Limiting

ABSTRACT The small multicopy plasmid pAMα1 (9.75 kb) encoding tetracycline resistance in Enterococcus faecalis is known to generate tandem repeats of a 4.1-kb segment carrying tet(L) when cells are grown extensively in the presence of tetracycline. Here we show that the initial (rate-limiting) step involves a site-specific recombination event involving plasmid-encoded relaxase activity acting at two recombination sequences (RS1 and RS2) that flank the tet determinant. We also present the complete nucleotide sequence of pAMα1.

Paxilline-negative mutants of Penicillium paxilli generated by heterologous and homologous plasmid integration

1998 ◽  
Vol 33 (5) ◽  
pp. 368-377 ◽  
Author(s):  
Carolyn Young ◽  
Yasuo Itoh ◽  
R. Johnson ◽  
I. Garthwaite ◽  
Christopher O. Miles ◽  
...  
Keyword(s):  
Plasmid Integration ◽  
Penicillium Paxilli

scholarly journals A Pathoadaptive Deletion in an Enteroaggregative Escherichia coli Outbreak Strain Enhances Virulence in a Caenorhabditis elegans Model

2010 ◽  
Vol 78 (9) ◽  
pp. 4068-4076 ◽  
Author(s):  
Jennifer Hwang ◽  
Lisa M. Mattei ◽  
Laura G. VanArendonk ◽  
Philip M. Meneely ◽  
Iruka N. Okeke
Keyword(s):  
Escherichia Coli ◽  
Caenorhabditis Elegans ◽  
Epithelial Cells ◽  
Genetic Material ◽  
Decarboxylase Activity ◽  
Multicopy Plasmid ◽  
Lysine Decarboxylase ◽  
Outbreak Strain ◽  
E Coli ◽  
C Elegans

ABSTRACT Enteroaggregative Escherichia coli (EAEC) strains are important diarrheal pathogens. EAEC strains are defined by their characteristic stacked-brick pattern of adherence to epithelial cells but show heterogeneous virulence and have different combinations of adhesin and toxin genes. Pathoadaptive deletions in the lysine decarboxylase (cad) genes have been noted among hypervirulent E. coli subtypes of Shigella and enterohemorrhagic E. coli. To test the hypothesis that cad deletions might account for heterogeneity in EAEC virulence, we developed a Caenorhabditis elegans pathogenesis model. Well-characterized EAEC strains were shown to colonize and kill C. elegans, and differences in virulence could be measured quantitatively. Of 49 EAEC strains screened for lysine decarboxylase activity, 3 tested negative. Most notable is isolate 101-1, which was recovered in Japan, from the largest documented EAEC outbreak. EAEC strain 101-1 was unable to decarboxylate lysine in vitro due to deletions in cadA and cadC, which, respectively, encode lysine decarboxylase and a transcriptional activator of the cadAB genes. Strain 101-1 was significantly more lethal to C. elegans than control strain OP50. Lethality was attenuated when the lysine decarboxylase defect was complemented from a multicopy plasmid and in single copy. In addition, restoring lysine decarboxylase function produced derivatives of 101-1 deficient in aggregative adherence to cultured human epithelial cells. Lysine decarboxylase inactivation is pathoadapative in an important EAEC outbreak strain, and deletion of cad genes could produce hypervirulent EAEC lineages in the future. These results suggest that loss, as well as gain, of genetic material can account for heterogeneous virulence among EAEC strains.

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