scholarly journals Cellular location and activity of Escherichia coli RecG proteins shed light on the function of its structurally unresolved C-terminus

2014 ◽  
Vol 42 (9) ◽  
pp. 5702-5714 ◽  
Author(s):  
Amy L. Upton ◽  
Jane I. Grove ◽  
Akeel A. Mahdi ◽  
Geoffrey S. Briggs ◽  
David S. Milner ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cellular Location ◽  
C Terminus ◽  
Shed Light

scholarly journals Clusters of Charged Residues at the C Terminus of MotA and N Terminus of MotB Are Important for Function of the Escherichia coli Flagellar Motor

2008 ◽  
Vol 190 (15) ◽  
pp. 5517-5521 ◽  
Author(s):  
Edan R. Hosking ◽  
Michael D. Manson
Keyword(s):  
Escherichia Coli ◽  
Flagellar Motor ◽  
Protein Levels ◽  
Partner Protein ◽  
C Terminus ◽  
N Terminus ◽  
Charged Residues ◽  
Positively Charged ◽  
Terminal Cluster

ABSTRACT MotA contains a conserved C-terminal cluster of negatively charged residues, and MotB contains a conserved N-terminal cluster of positively charged residues. Charge-altering mutations affecting these residues impair motility but do not diminish Mot protein levels. The motility defects are reversed by second-site mutations targeting the same or partner protein.

scholarly journals Secretion Defects That Activate the Phage Shock Response of Escherichia coli

2003 ◽  
Vol 185 (22) ◽  
pp. 6707-6711 ◽  
Author(s):  
Susan E. Jones ◽  
Louise J. Lloyd ◽  
Kum K. Tan ◽  
Martin Buck
Keyword(s):  
Escherichia Coli ◽  
Inner Membrane ◽  
Cellular Location ◽  
Shock Response

ABSTRACT The phage shock protein (psp) operon of Escherichia coli is induced by membrane-damaging cues. Earlier studies linked defects in secretion across the inner membrane to induction of the psp response. Here we show that defects in yidC and sec secretion induce psp but that defects in tat and srp have no effect. We have also determined the cellular location of PspB and PspD proteins.

scholarly journals The C-Terminal Flexible Domain of the Heme Chaperone CcmE Is Important but Not Essential for Its Function

2003 ◽  
Vol 185 (13) ◽  
pp. 3821-3827 ◽  
Author(s):  
Elisabeth Enggist ◽  
Linda Thöny-Meyer
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Heme Binding ◽  
Membrane Anchor ◽  
Terminal Domain ◽  
Conserved Domain ◽  
C Terminus ◽  
Helical Turn ◽  
Low Activity

ABSTRACT CcmE is a heme chaperone active in the cytochrome c maturation pathway of Escherichia coli. It first binds heme covalently to strictly conserved histidine H130 and subsequently delivers it to apo-cytochrome c. The recently solved structure of soluble CcmE revealed a compact core consisting of a β-barrel and a flexible C-terminal domain with a short α-helical turn. In order to elucidate the function of this poorly conserved domain, CcmE was truncated stepwise from the C terminus. Removal of all 29 amino acids up to crucial histidine 130 did not abolish heme binding completely. For detectable transfer of heme to type c cytochromes, only one additional residue, D131, was required, and for efficient cytochrome c maturation, the seven-residue sequence 131DENYTPP137 was required. When soluble forms of CcmE were expressed in the periplasm, the C-terminal domain had to be slightly longer to allow detection of holo-CcmE. Soluble full-length CcmE had low activity in cytochrome c maturation, indicating the importance of the N-terminal membrane anchor for the in vivo function of CcmE.

scholarly journals The C-Terminal Domain of MinC Inhibits Assembly of the Z Ring in Escherichia coli

2006 ◽  
Vol 189 (1) ◽  
pp. 236-243 ◽  
Author(s):  
Daisuke Shiomi ◽  
William Margolin
Keyword(s):  
Escherichia Coli ◽  
Cell Division ◽  
Fluorescent Protein ◽  
Additional Function ◽  
Ring Assembly ◽  
C Terminus ◽  
Min Proteins ◽  
Z Ring ◽  
Ftsz Assembly ◽  
Green Fluorescent

ABSTRACT In Escherichia coli, the Min system, consisting of three proteins, MinC, MinD, and MinE, negatively regulates FtsZ assembly at the cell poles, helping to ensure that the Z ring will assemble only at midcell. Of the three Min proteins, MinC is sufficient to inhibit Z-ring assembly. By binding to MinD, which is mostly localized at the membrane near the cell poles, MinC is sequestered away from the cell midpoint, increasing the probability of Z-ring assembly there. Previously, it has been shown that the two halves of MinC have two distinct functions. The N-terminal half is sufficient for inhibition of FtsZ assembly, whereas the C-terminal half of the protein is required for binding to MinD as well as to a component of the division septum. In this study, we discovered that overproduction of the C-terminal half of MinC (MinC122-231) could also inhibit cell division and that this inhibition was at the level of Z-ring disassembly and dependent on MinD. We also found that fusing green fluorescent protein to either the N-terminal end of MinC122-231, the C terminus of full-length MinC, or the C terminus of MinC122-231 perturbed MinC function, which may explain why cell division inhibition by MinC122-231 was not detected previously. These results suggest that the C-terminal half of MinC has an additional function in the regulation of Z-ring assembly.

scholarly journals Acquisition of virulence-associated factors by the enteric pathogens Escherichia coli and Salmonella enterica

2001 ◽  
Vol 356 (1411) ◽  
pp. 1027-1034 ◽  
Author(s):  
John Wain ◽  
Deborah House ◽  
Derek Pickard ◽  
Gordon Dougan ◽  
Gad Frankel
Keyword(s):  
Escherichia Coli ◽  
Genetic Variation ◽  
Salmonella Enterica ◽  
Associated Factors ◽  
Enteric Pathogens ◽  
Genomic Studies ◽  
Shed Light

In this review we summarize recent genomic studies that shed light on the mechanism through which pathogenic Escherichia coli and Salmonella enterica have evolved. We show how acquisition of DNA at specific sites on the chromosome has contributed to increased genetic variation and virulence of these two genera of the Enterobacteriaceae.

Role of the C Terminus of FtsK in Escherichia coli Chromosome Segregation

1998 ◽  
Vol 180 (23) ◽  
pp. 6424-6428 ◽  
Author(s):  
Xuan-Chuan Yu ◽  
Elizabeth K. Weihe ◽  
William Margolin
Keyword(s):  
Escherichia Coli ◽  
Chromosome Segregation ◽  
C Terminus

scholarly journals Mutational Analysis of Residues in PriA and PriC Affecting Their Ability To Interact with SSB in Escherichia coli K-12

2020 ◽  
Vol 202 (23) ◽  
Author(s):  
Anastasiia N. Klimova ◽  
Steven J. Sandler
Keyword(s):  
Escherichia Coli ◽  
Mutational Analysis ◽  
Wild Type ◽  
Content Type ◽  
Growth Defects ◽  
C Terminus ◽  
K 12 ◽  
And Function

ABSTRACT Escherichia coli PriA and PriC recognize abandoned replication forks and direct reloading of the DnaB replicative helicase onto the lagging-strand template coated with single-stranded DNA-binding protein (SSB). Both PriA and PriC have been shown by biochemical and structural studies to physically interact with the C terminus of SSB. In vitro, these interactions trigger remodeling of the SSB on ssDNA. priA341(R697A) and priC351(R155A) negated the SSB remodeling reaction in vitro. Plasmid-carried priC351(R155A) did not complement priC303::kan, and priA341(R697A) has not yet been tested for complementation. Here, we further studied the SSB-binding pockets of PriA and PriC by placing priA341(R697A), priA344(R697E), priA345(Q701E), and priC351(R155A) on the chromosome and characterizing the mutant strains. All three priA mutants behaved like the wild type. In a ΔpriB strain, the mutations caused modest increases in SOS expression, cell size, and defects in nucleoid partitioning (Par−). Overproduction of SSB partially suppressed these phenotypes for priA341(R697A) and priA344(R697E). The priC351(R155A) mutant behaved as expected: there was no phenotype in a single mutant, and there were severe growth defects when this mutation was combined with ΔpriB. Analysis of the priBC mutant revealed two populations of cells: those with wild-type phenotypes and those that were extremely filamentous and Par− and had high SOS expression. We conclude that in vivo, priC351(R155A) identified an essential residue and function for PriC, that PriA R697 and Q701 are important only in the absence of PriB, and that this region of the protein may have a complicated relationship with SSB. IMPORTANCE Escherichia coli PriA and PriC recruit the replication machinery to a collapsed replication fork after it is repaired and needs to be restarted. In vitro studies suggest that the C terminus of SSB interacts with certain residues in PriA and PriC to recruit those proteins to the repaired fork, where they help remodel it for restart. Here, we placed those mutations on the chromosome and tested the effect of mutating these residues in vivo. The priC mutation completely abolished function. The priA mutations had no effect by themselves. They did, however, display modest phenotypes in a priB-null strain. These phenotypes were partially suppressed by SSB overproduction. These studies give us further insight into the reactions needed for replication restart.

scholarly journals Involvement of σ S accumulation in repression of the flhDC operon in acidic phospholipid-deficient mutants of Escherichia coli

Microbiology ◽  
2010 ◽  
Vol 156 (6) ◽  
pp. 1650-1660 ◽  
Author(s):  
Junji Uchiyama ◽  
Yuka Nobue ◽  
Hong Zhao ◽  
Hiroshi Matsuzaki ◽  
Hideki Nagahama ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Molecular Mechanism ◽  
Sharp Increase ◽  
Mrna Level ◽  
Acidic Phospholipid ◽  
High Level ◽  
Mutant Cells ◽  
Shed Light

Escherichia coli pgsA mutations, which cause acidic phospholipid deficiency, repress transcription of the flagellar master operon flhDC, and thus impair flagellar formation and motility. The molecular mechanism of the strong repression of flhDC transcription in the mutant cells, however, has not yet been clarified. In order to shed light on this mechanism we isolated genes which, when supplied in multicopy, suppress the repression of flhD, and found that three genes, gadW, metE and yeaB, were capable of suppression. Taking into account a previous report that gadW represses σ S production, the level of σ S in the pgsA3 mutant was examined. We found that pgsA3 cells had a high level of σ S and that introduction of a gadW plasmid into pgsA3 cells did reduce the σ S level. The pgsA3 cells exhibited a sharp increase in σ S levels that can only be partially attributed to the slight increase in rpoS transcription; the largest part of the effect is due to a post-transcriptional accumulation of σ S. GadW in multicopy exerts its effect by post-transcriptionally downregulating σ S. YeaB and MetE in multicopy also exert their effect via σ S. Disruption of rpoS caused an increase of the flhD mRNA level, and induction from P trc -rpoS repressed the flhD mRNA level. The strong repression of flhD transcription in pgsA3 mutant cells is thus suggested to be caused by the accumulated σ S.

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