A 718-kb DNA Sequence of the Escherichia coli K-12 Genome Corresponding to the 12.7-28.0 min Region on the Linkage Map

Oshima, Taku; Aiba, Hirofumi; Baba, Tomoya; Fujita, Katsutoshi; Hayashi, Kouji; Honjo, Atsuko; Ikemoto, K.; Inada, Toshifumi; Itoh, Takeshi; Kajihara, Miwako; Kanai, K.; Kashimoto, Kaoru; Kimura, Shigenobu; Kitagawa, Masanari; Makino, Kozo; Masuda, Shinji; Miki, Takeyoshi; Mizobuchi, Kiyoshi; Mori, Hirotada; Motomura, K.; Nakamura, Yoshikazu; Nashimoto, H; Nishio, Y.; Saito, Noriko; Sampei, G.; Seki, Y.; Tagami, Hideaki; Takemoto, Kazuhiro; Wada, Chieko; Yamamoto, Yoshihiro; Yano, Masaki; Horiuchi, Takashi

doi:10.1093/dnares/3.3.137

Cited by 58 publications

(23 citation statements)

References 11 publications

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“…1 A). The recent determination of the organization of the aqpZ gene in E. coli predicted that it is a monocistronic message (8,10). As shown here, the size of the 0.7-kb transcript (Fig.…”

Section: Discussionsupporting

confidence: 53%

“…The functional characterization of AqpZ demonstrated waterselectivity with negligible glycerol transport (6), whereas the sequence-related protein GlpF exhibited the opposite specificity (7). The genomic organization of aqpZ has been defined in E. coli (8)(9)(10), and Southern blot analysis demonstrated cross-hybridizing bands in multiple Gram-negative and Grampositive bacteria (6). Genomic sequencing has uncovered aqpZ-like genes in Haemophilus influenzae (11); Mycoplasma genitalium, a prokaryote lacking a cell wall (12); and Synechocystis sp.…”

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confidence: 99%

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Regulation of the Escherichia coli water channel gene aqpZ

Calamita

Kempf

Bonhivers

et al. 1998

Proc. Natl. Acad. Sci. U.S.A.

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Osmotic movement of water across bacterial cell membranes is postulated to be a homeostatic mechanism for maintaining cell turgor. The molecular water transporter remained elusive until discovery of the Escherichia coli water channel, AqpZ, however the regulation of the aqpZ gene expression and physiological function of the AqpZ protein are unknown. Northern analysis revealed a transcript of 0.7 kb, confirming the monocistronic nature of aqpZ. Regulatory studies performed with an aqpZ::lacZ low copy plasmid demonstrate enhanced expression during mid-logarithmic growth, and expression of the gene is dependent upon the extracellular osmolality, which increased in hypoosmotic environments but strongly reduced in hyperosmolar NaCl or KCl. While disruption of the chromosomal aqpZ is not lethal for E. coli, the colonies of the aqpZ knockout mutant are smaller than those of the parental wild-type strain. When cocultured with parental wild-type E. coli, the aqpZ knockout mutant exhibits markedly reduced colony formation when grown at 39°C. Similarly, the aqpZ knockout mutant also exhibits greatly reduced colony formation when grown at low osmolality, but this phenotype is reversed by overexpression of AqpZ protein. These results implicate AqpZ as a participant in the adaptive response of E. coli to hypoosmotic environments and indicate a requirement for AqpZ by rapidly growing cells.

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“…1 A). The recent determination of the organization of the aqpZ gene in E. coli predicted that it is a monocistronic message (8,10). As shown here, the size of the 0.7-kb transcript (Fig.…”

Section: Discussionsupporting

confidence: 53%

mentioning

confidence: 99%

Regulation of the Escherichia coli water channel gene aqpZ

Calamita

Kempf

Bonhivers

et al. 1998

Proc. Natl. Acad. Sci. U.S.A.

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“…1B). The sequence of this region (Oshima et al, 1996) does not show any recognizable rho-independent transcription terminators (Lesnik et al, 2001). However, two pairs of inverted repeats were recognized beyond the ychF termination codon.…”

Section: H-ends Of Transcripts Containing Ychf Sequencesmentioning

confidence: 87%

Transcriptional analysis of the gene encoding peptidyl-tRNA hydrolase in Escherichia coli

2002

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Gene pth encodes peptidyl-tRNA hydrolase (Pth), an enzyme that cleaves peptidyl-tRNAs released abortively from ribosomes during protein synthesis. In the Escherichia coli chromosome, pth is flanked by ychH and ychF, two genes of unknown function. Pth is essential for cell viability, especially under conditions leading to overproduction of peptidyl-tRNA. In an attempt to unveil the elements that affect pth expression, the transcriptional features of the pth region were investigated. Northern blot experiments showed that both pth and ychF, the 3'-proximal gene, are cotranscribed in a bicistronic transcript. However, transcripts containing each of the individual messages were also detected. Accordingly, two transcriptional promoters were identified by primer extension experiments : one located upstream of pth, which presumably gives rise to both the mono and bicistronic pth transcripts, and the other, preceding ychF, which generates its monocistronic message. Deletion analysis indicates that pth transcript stability depends on ychF integrity. Also, a defect in RNase E activity resulted in Pth overproduction. It is proposed that RNase E processing within ychF in the bicistronic message limits pth expression.

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“…When the optical density (A 600 ) reached 0.5, 1 mm IPTG was included and incubation was continued for 3 h. Whole cell lysates prepared from cells before and after IPTG induction were analysed by SDS-polyacrylamide (16%) gel electrophoresis and Coomassie Brilliant Blue staining. (Oshima et al 1996;Blattner et al 1997). We named this novel gene hspQ (heat shock protein Q), based on the following findings.…”

Section: Isolation and Identification Of Hspqmentioning

confidence: 99%

Novel heat shock protein HspQ stimulates the degradation of mutant DnaA protein in Escherichia coli

et al. 2004

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Escherichia coli DnaA protein initiates chromosomal replication and is an important regulatory target during the replication cycle. In this study, a suppressor mutation isolated by transposon mutagenesis was found to allow growth of the temperature-sensitive dnaA508 and dnaA167 mutants at 40 °°°° C. The suppressor consists of a transposon insertion in a previously annotated ORF, here termed hspQ , a novel heat shock gene whose promoter is recognized by the major heat shock sigma factor σ σ σ σ 32. Expression of hspQ on a pBR322 derivative inhibits growth of the dnaA508 and dnaA167 mutants at 30 °°°° C, whereas growth of dnaA46 and other dnaA mutants is insensitive to changes in the level of hspQ . Cellular DnaA508 protein is degraded rapidly at elevated temperature, but hspQ disruption impedes this process. In contrast, DnaA46 protein is rapidly degraded in an hspQ -independent manner. Gel-filtration and chemical cross-linking experiments suggest that HspQ forms a stable homodimer in solution and can form homomultimers consisting of about four monomers. Heat-shock induced proteases such as Clp contain homomultimers of subunit proteins. We propose that HspQ is a new factor involved in the quality control of proteins and that it functions by excluding denatured proteins.

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A 718-kb DNA Sequence of the Escherichia coli K-12 Genome Corresponding to the 12.7-28.0 min Region on the Linkage Map

Cited by 58 publications

References 11 publications

Regulation of the Escherichia coli water channel gene aqpZ

Regulation of the Escherichia coli water channel gene aqpZ

Transcriptional analysis of the gene encoding peptidyl-tRNA hydrolase in Escherichia coli

Novel heat shock protein HspQ stimulates the degradation of mutant DnaA protein in Escherichia coli

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