Faculty Opinions recommendation of The E. coli BtuCD structure: a framework for ABC transporter architecture and mechanism.

2002 ◽  
Author(s):  
Catherine Drennan
Keyword(s):  
Abc Transporter ◽  
E Coli

scholarly journals Enhancement of the Efficiency of Secretion of Heterologous Lipase in Escherichia coli by Directed Evolution of the ABC Transporter System

2005 ◽  
Vol 71 (7) ◽  
pp. 3468-3474 ◽  
Author(s):  
Gyeong Tae Eom ◽  
Jae Kwang Song ◽  
Jung Hoon Ahn ◽  
Yeon Soo Seo ◽  
Joon Shick Rhee
Keyword(s):  
Escherichia Coli ◽  
Directed Evolution ◽  
Abc Transporter ◽  
Microtiter Plate ◽  
Single Amino Acid ◽  
Wild Type ◽  
E Coli ◽  
Single Amino Acid Change ◽  
Secretion Efficiency

ABSTRACT The ABC transporter (TliDEF) from Pseudomonas fluorescens SIK W1, which mediated the secretion of a thermostable lipase (TliA) into the extracellular space in Escherichia coli, was engineered using directed evolution (error-prone PCR) to improve its secretion efficiency. TliD mutants with increased secretion efficiency were identified by coexpressing the mutated tliD library with the wild-type tliA lipase in E. coli and by screening the library with a tributyrin-emulsified indicator plate assay and a microtiter plate-based assay. Four selected mutants from one round of error-prone PCR mutagenesis, T6, T8, T24, and T35, showed 3.2-, 2.6-, 2.9-, and 3.0-fold increases in the level of secretion of TliA lipase, respectively, but had almost the same level of expression of TliD in the membrane as the strain with the wild-type TliDEF transporter. These results indicated that the improved secretion of TliA lipase was mediated by the transporter mutations. Each mutant had a single amino acid change in the predicted cytoplasmic regions in the membrane domain of TliD, implying that the corresponding region of TliD was important for the improved and successful secretion of the target protein. We therefore concluded that the efficiency of secretion of a heterologous protein in E. coli can be enhanced by in vitro engineering of the ABC transporter.

scholarly journals A Predicted ABC Transporter, FtsEX, Is Needed for Cell Division in Escherichia coli

2004 ◽  
Vol 186 (3) ◽  
pp. 785-793 ◽  
Author(s):  
Kari L. Schmidt ◽  
Nicholas D. Peterson ◽  
Ryan J. Kustusch ◽  
Mark C. Wissel ◽  
Becky Graham ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cell Division ◽  
Abc Transporter ◽  
Luria Bertani ◽  
Wild Type ◽  
E Coli ◽  
Division Site ◽  
Site Localization ◽  
Free Media ◽  
Mass Increase

ABSTRACT FtsE and FtsX have homology to the ABC transporter superfamily of proteins and appear to be widely conserved among bacteria. Early work implicated FtsEX in cell division in Escherichia coli, but this was subsequently challenged, in part because the division defects in ftsEX mutants are often salt remedial. Strain RG60 has an ftsE::kan null mutation that is polar onto ftsX. RG60 is mildly filamentous when grown in standard Luria-Bertani medium (LB), which contains 1% NaCl, but upon shift to LB with no NaCl growth and division stop. We found that FtsN localizes to potential division sites, albeit poorly, in RG60 grown in LB with 1% NaCl. We also found that in wild-type E. coli both FtsE and FtsX localize to the division site. Localization of FtsX was studied in detail and appeared to require FtsZ, FtsA, and ZipA, but not the downstream division proteins FtsK, FtsQ, FtsL, and FtsI. Consistent with this, in media lacking salt, FtsA and ZipA localized independently of FtsEX, but the downstream proteins did not. Finally, in the absence of salt, cells depleted of FtsEX stopped dividing before any change in growth rate (mass increase) was apparent. We conclude that FtsEX participates directly in the process of cell division and is important for assembly or stability of the septal ring, especially in salt-free media.

scholarly journals Structure of MlaFB uncovers novel mechanisms of ABC transporter regulation

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Ljuvica R Kolich ◽  
Ya-Ting Chang ◽  
Nicolas Coudray ◽  
Sabrina I Giacometti ◽  
Mark R MacRae ◽  
...  
Keyword(s):  
Abc Transporter ◽  
Abc Transporters ◽  
Membrane Integrity ◽  
Regulatory Mechanisms ◽  
Nucleotide Binding Domain ◽  
E Coli ◽  
Small Proteins ◽  
Transporter Family ◽  
Bacterial Lipid ◽  
Lipid Transporter

ABC transporters facilitate the movement of diverse molecules across cellular membranes, but how their activity is regulated post-translationally is not well understood. Here we report the crystal structure of MlaFB from E. coli, the cytoplasmic portion of the larger MlaFEDB ABC transporter complex, which drives phospholipid trafficking across the bacterial envelope to maintain outer membrane integrity. MlaB, a STAS domain protein, binds the ABC nucleotide binding domain, MlaF, and is required for its stability. Our structure also implicates a unique C-terminal tail of MlaF in self-dimerization. Both the C-terminal tail of MlaF and the interaction with MlaB are required for the proper assembly of the MlaFEDB complex and its function in cells. This work leads to a new model for how an important bacterial lipid transporter may be regulated by small proteins, and raises the possibility that similar regulatory mechanisms may exist more broadly across the ABC transporter family.

scholarly journals Enhanced Wound Healing by Recombinant Escherichia coli Nissle 1917 via Human Epidermal Growth Factor Receptor in Human Intestinal Epithelial Cells: Therapeutic Implication Using Recombinant Probiotics

2011 ◽  
Vol 80 (3) ◽  
pp. 1079-1087 ◽  
Author(s):  
Hye Jin Choi ◽  
Jung Hoon Ahn ◽  
Seong-Hwan Park ◽  
Kee Hun Do ◽  
Juil Kim ◽  
...  
Keyword(s):  
Wound Healing ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Abc Transporter ◽  
Egf Receptor ◽  
Mitogen Activated Protein Kinase ◽  
Content Type ◽  
E Coli ◽  
Epithelial Migration ◽  
Epidermal Growth

The gastrointestinal mucosa has a remarkable ability to repair damage with the support of epidermal growth factor (EGF), which stimulates epithelial migration and proliferative reepithelialization. For the treatment of mucosal injuries, it is important to develop efficient methods for the localized delivery of mucoactive biotherapeutics. The basic idea in the present study came from the assumption that an intestinal probiotic vehicle can carry and deliver key recombinant medicinal proteins to the injured epithelial target in patients with intestinal ulcerative diseases, including inflammatory bowel disease. The study was focused on the use of the safe probioticE. coliNissle 1917, which was constructed to secrete human EGF in conjunction with the lipase ABC transporter recognition domain (LARD). Using thein vitrophysically wounded monolayer model, ABC transporter-mediated EGF secretion by probioticE. coliNissle 1917 was demonstrated to enhance the wound-healing migration of human enterocytes. Moreover, the epithelial wound closure was dependent on EGF receptor-linked activation, which exclusively involved the subsequent signaling pathway of the mitogen-activated protein kinase kinase (MEK) extracellular-related kinases 1 and 2 (ERK1/2). In particular, the migrating frontier of the wounded edge displayed the strongest EGF receptor-linked signaling activation in the presence of the recombinant probiotic. The present study provides a basis for the clinical application of human recombinant biotherapeutics via an efficient, safe probiotic vehicle.

scholarly journals The High-Affinity E. coli Methionine ABC Transporter: Structure and Allosteric Regulation

Science ◽  
2008 ◽  
Vol 321 (5886) ◽  
pp. 250-253 ◽  
Author(s):  
N. S. Kadaba ◽  
J. T. Kaiser ◽  
E. Johnson ◽  
A. Lee ◽  
D. C. Rees
Keyword(s):  
Abc Transporter ◽  
Allosteric Regulation ◽  
E Coli ◽  
High Affinity ◽  
Transporter Structure

scholarly journals The SecB Chaperone Is Bifunctional in Serratia marcescens: SecB Is Involved in the Sec Pathway and Required for HasA Secretion by the ABC Transporter

2003 ◽  
Vol 185 (1) ◽  
pp. 80-88 ◽  
Author(s):  
Guillaume Sapriel ◽  
Cécile Wandersman ◽  
Philippe Delepelaire
Keyword(s):  
Serratia Marcescens ◽  
Abc Transporter ◽  
Point Mutations ◽  
Inner Membrane ◽  
E Coli ◽  
Sec Pathway ◽  
Secretion Pathway ◽  
Abc Protein ◽  
Inner Membrane Protein ◽  
Secretion Pathways

ABSTRACT HasA is the secreted hemophore of the heme acquisition system (Has) of Serratia marcescens. It is secreted by a specific ABC transporter apparatus composed of three proteins: HasD, an inner membrane ABC protein; HasE, another inner membrane protein; and HasF, a TolC homolog. Except for HasF, the structural genes of the Has system are encoded by an iron-regulated operon. In previous studies, this secretion system has been reconstituted in Escherichia coli, where it requires the presence of the SecB chaperone, the Sec pathway-dedicated chaperone. We cloned and inactivated the secB gene from S. marcescens. We show that S. marcescens SecB is 93% identical to E. coli SecB and complements the secretion defects of a secB mutant of E. coli for both the Sec and ABC pathways of HasA secretion. In S. marcescens, SecB inactivation affects translocation by the Sec pathway and abolishes HasA secretion. This demonstrates that S. marcescens SecB is the genuine chaperone for HasA secretion in S. marcescens. These results also demonstrate that S. marcescens SecB is bifunctional, as it is involved in two separate secretion pathways. We investigated the effects of secB point mutations in the reconstituted HasA secretion pathway by comparing the translocation of a Sec substrate in various mutants. Two different patterns of SecB residue effects were observed, suggesting that SecB functions may differ for the Sec and ABC pathways.

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