Polarity and the regulation of the ilv gene cluster in Escherichia coli strain K-12

1976 ◽  
Vol 148 (2) ◽  
pp. 111-124 ◽  
Author(s):  
John M. Smith ◽  
David E. Smolin ◽  
H. Edwin Umbarger
Keyword(s):  
Escherichia Coli ◽  
Gene Cluster ◽  
Coli Strain ◽  
K 12

scholarly journals The Pathogenicity Island-Associated K15 Capsule Determinant Exhibits a Novel Genetic Structure and Correlates with Virulence in Uropathogenic Escherichia coli Strain 536

2004 ◽  
Vol 72 (10) ◽  
pp. 5993-6001 ◽  
Author(s):  
György Schneider ◽  
Ulrich Dobrindt ◽  
Holger Brüggemann ◽  
Gábor Nagy ◽  
Britta Janke ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Gene Cluster ◽  
Pathogenicity Island ◽  
Coli Strain ◽  
Open Reading Frames ◽  
E Coli ◽  
Secretion Pathway ◽  
Encoding Gene ◽  
Group 2 ◽  
K 12

ABSTRACT The K15 capsule determinant of uropathogenic Escherichia coli strain 536 (O6:K15:H31) is part of a novel 79.6-kb pathogenicity island (PAI) designated PAI V536 that is absent from the genome of nonpathogenic E. coli K-12 strain MG1655. PAI V536 shows typical characteristics of a composite PAI that is associated with the pheV tRNA gene and contains the pix fimbriae determinant as well as genes coding for a putative phosphoglycerate transport system, an autotransporter protein, and hypothetical open reading frames. A gene cluster coding for a putative general secretion pathway system, together with a kps K15 determinant, is localized downstream of a truncated pheV gene (′pheV) also present in this chromosomal region. The distribution of genes present on PAI V536 was studied by PCR in different pathogenic and nonpathogenic E. coli isolates of various sources. Analysis of the 20-kb kps locus revealed a so far unknown genetic organization. Generally, the kps K15 gene cluster resembles that of group 2 and 3 capsules, where two conserved regions (regions 1 and 3) are located up- or downstream of a highly variable serotype-specific region (region 2). Interestingly, recombination of a group 2 and 3 determinant may have been involved in the evolution of the K15 capsule-encoding gene cluster. Expression of the K15 capsule is important for virulence in a murine model of ascending urinary tract infection but not for serum resistance of E. coli strain 536.

scholarly journals Lambda Transducing Phage and Clones Carrying Genes of the cysJIHDC Gene Cluster of Escherichia coli K 12

Microbiology ◽  
1987 ◽  
Vol 133 (10) ◽  
pp. 2707-2717
Author(s):  
C. L. Hunt ◽  
V. Colless ◽  
M. T. Smith ◽  
D. O. Molasky ◽  
M. S. Malo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Gene Cluster ◽  
K 12

Linkage map of Escherichia coli strain K-12.

1972 ◽  
Vol 36 (4) ◽  
pp. 504-524 ◽  
Author(s):  
A L Taylor ◽  
C D Trotter
Keyword(s):  
Escherichia Coli ◽  
Linkage Map ◽  
Coli Strain ◽  
K 12

scholarly journals The Putrescine Importer PuuP of Escherichia coli K-12

2009 ◽  
Vol 191 (8) ◽  
pp. 2776-2782 ◽  
Author(s):  
Shin Kurihara ◽  
Yuichi Tsuboi ◽  
Shinpei Oda ◽  
Hyeon Guk Kim ◽  
Hidehiko Kumagai ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Gene Cluster ◽  
Growth Phase ◽  
Exponential Growth ◽  
Minimal Medium ◽  
Exponential Growth Phase ◽  
E Coli ◽  
Genes Encoding ◽  
K 12 ◽  
Utilization Pathway

ABSTRACT The Puu pathway is a putrescine utilization pathway involving gamma-glutamyl intermediates. The genes encoding the enzymes of the Puu pathway form a gene cluster, the puu gene cluster, and puuP is one of the genes in this cluster. In Escherichia coli, three putrescine importers, PotFGHI, PotABCD, and PotE, were discovered in the 1990s and have been studied; however, PuuP had not been discovered previously. This paper shows that PuuP is a novel putrescine importer whose kinetic parameters are equivalent to those of the polyamine importers discovered previously. A puuP + strain absorbed up to 5 mM putrescine from the medium, but a ΔpuuP strain did not. E. coli strain MA261 has been used in previous studies of polyamine transporters, but PuuP had not been identified previously. It was revealed that the puuP gene of MA261 was inactivated by a point mutation. When E. coli was grown on minimal medium supplemented with putrescine as the sole carbon or nitrogen source, only PuuP among the polyamine importers was required. puuP was expressed strongly when putrescine was added to the medium or when the puuR gene, which encodes a putative repressor, was deleted. When E. coli was grown in M9-tryptone medium, PuuP was expressed mainly in the exponential growth phase, and PotFGHI was expressed independently of the growth phase.

scholarly journals The Oxidoreductase DsbA Plays a Key Role in the Ability of the Crohn's Disease-Associated Adherent-Invasive Escherichia coli Strain LF82 To Resist Macrophage Killing

2007 ◽  
Vol 189 (13) ◽  
pp. 4860-4871 ◽  
Author(s):  
Marie-Agnès Bringer ◽  
Nathalie Rolhion ◽  
Anne-Lise Glasser ◽  
Arlette Darfeuille-Michaud
Keyword(s):  
Escherichia Coli ◽  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Coli Strain ◽  
Intestinal Epithelial ◽  
Type 1 Pili ◽  
K 12

ABSTRACT Adherent-invasive Escherichia coli (AIEC) isolated from Crohn's disease patients is able to adhere to and invade intestinal epithelial cells and to replicate in mature phagolysosomes within macrophages. Here, we show that the dsbA gene, encoding a periplasmic oxidoreductase, was required for AIEC strain LF82 to adhere to intestinal epithelial cells and to survive within macrophages. The LF82-ΔdsbA mutant did not express flagella and, probably as a consequence of this, did not express type 1 pili. The role of DsbA in adhesion is restricted to the loss of flagella and type 1 pili, as forced contact between bacteria and cells and induced expression of type 1 pili restored the wild-type phenotype. In contrast, the dsbA gene is essential for AIEC LF82 bacteria to survive within macrophages, irrespective of the loss of flagella and type 1 pilus expression, and the survival ability of LF82-ΔdsbA was as low as that of the nonpathogenic E. coli K-12, which was efficiently killed by macrophages. We also provide evidence that the dsbA gene is needed for LF82 bacteria to grow and survive in an acidic and nutrient-poor medium that partly mimics the harsh environment of the phagocytic vacuole. In addition, under such stress conditions dsbA transcription is highly up-regulated. Finally, the CpxRA signaling pathway does not play a role in regulation of dsbA expression in AIEC LF82 bacteria under conditions similar to those of mature phagolysosomes.

scholarly journals Gene Cluster for Assembly of Pilus Colonization Factor Antigen III of Enterotoxigenic Escherichia coli

2001 ◽  
Vol 69 (9) ◽  
pp. 5864-5873 ◽  
Author(s):  
Tooru Taniguchi ◽  
Yukihiro Akeda ◽  
Ayako Haba ◽  
Yoko Yasuda ◽  
Koichiro Yamamoto ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Nucleotide Sequence ◽  
Gene Cluster ◽  
Enterotoxigenic Escherichia Coli ◽  
Human Colon Carcinoma Cell ◽  
E Coli ◽  
Colonization Factor ◽  
Type Iv ◽  
K 12 ◽  
Factor Antigen

ABSTRACT The assembly of pilus colonization factor antigen III (CFA/III) of enterotoxigenic Escherichia coli (ETEC) requires the processing of CFA/III major pilin (CofA) by a prepilin peptidase (CofP), similar to other type IV pilus formation systems. CofA is produced initially as a 26.5-kDa preform pilin (prepilin) and then processed to a 20.5-kDa mature pilin by CofP which is predicted to be localized in the inner membrane. In the present experiment, we determined the nucleotide sequence of the whole region for CFA/III formation and identified a cluster of 14 genes, includingcofA and cofP. Several proteins encoded bycof genes were similar to previously described proteins, such as the toxin-coregulated pili of Vibrio cholerae and the bundle-forming pili of enteropathogenic E. coli. The G+C content of the cof gene cluster was 37%, which was significantly lower than the average for the E. coli genome (50%). The introduction of a recombinant plasmid containing thecof gene cluster into the E. coli K-12 strain conferred CFA/III biogenesis and the ability of adhesion to the human colon carcinoma cell line Caco-2. This is the first report of a complete nucleotide sequence of the type IV pili found in human ETEC, and our results provide a useful model for studying the molecular mechanism of CFA/III biogenesis and the role of CFA/III in ETEC infection.

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