Insights into the structure of Escherichia coli outer membrane as the target for engineering microbial cell factories

AbstractEscherichia coli is generally used as model bacteria to define microbial cell factories for many products and to investigate regulation mechanisms. E. coli exhibits phospholipids, lipopolysaccharides, colanic acid, flagella and type I fimbriae on the outer membrane which is a self-protective barrier and closely related to cellular morphology, growth, phenotypes and stress adaptation. However, these outer membrane associated molecules could also lead to potential contamination and insecurity for fermentation products and consume lots of nutrients and energy sources. Therefore, understanding critical insights of these membrane associated molecules is necessary for building better microbial producers. Here the biosynthesis, function, influences, and current membrane engineering applications of these outer membrane associated molecules were reviewed from the perspective of synthetic biology, and the potential and effective engineering strategies on the outer membrane to improve fermentation features for microbial cell factories were suggested.

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Reverse engineering of fatty acid-tolerant Escherichia coli identifies design strategies for robust microbial cell factories

Metabolic Engineering ◽

10.1016/j.ymben.2020.05.001 ◽

2020 ◽

Vol 61 ◽

pp. 120-130 ◽

Cited By ~ 1

Author(s):

Yingxi Chen ◽

Erin E. Boggess ◽

Efrain Rodriguez Ocasio ◽

Aric Warner ◽

Lucas Kerns ◽

...

Keyword(s):

Escherichia Coli ◽

Fatty Acid ◽

Reverse Engineering ◽

Microbial Cell ◽

Design Strategies ◽

Microbial Cell Factories ◽

Cell Factories ◽

Acid Tolerant

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ESCHERICHIA COLI REDOX MUTANTS AS MICROBIAL CELL FACTORIES FOR THE SYNTHESIS OF REDUCED BIOCHEMICALS

Computational and Structural Biotechnology Journal ◽

10.5936/csbj.201210019 ◽

2012 ◽

Vol 3 (4) ◽

pp. e201210019 ◽

Cited By ~ 20

Author(s):

Jimena A. Ruiz ◽

Alejandra de Almeida ◽

Manuel S. Godoy ◽

Mariela P. Mezzina ◽

Gonzalo N. Bidart ◽

...

Keyword(s):

Escherichia Coli ◽

Microbial Cell ◽

Microbial Cell Factories ◽

Cell Factories

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The Activity of Escherichia coli Chaperone SurA Is Regulated by Conformational Changes Involving a Parvulin Domain

Journal of Bacteriology ◽

10.1128/jb.00889-15 ◽

2016 ◽

Vol 198 (6) ◽

pp. 921-929 ◽

Cited By ~ 22

Author(s):

Garner R. Soltes ◽

Jaclyn Schwalm ◽

Dante P. Ricci ◽

Thomas J. Silhavy

Keyword(s):

Escherichia Coli ◽

Outer Membrane ◽

Conformational Changes ◽

Outer Membrane Proteins ◽

Membrane Integrity ◽

Minor Importance ◽

Type I ◽

Peptidyl Prolyl Isomerase ◽

Content Type ◽

Type I Fimbriae

ABSTRACTThe periplasmic chaperone SurA is critical for the biogenesis of outer membrane proteins (OMPs) and, thus, the maintenance of membrane integrity inEscherichia coli. The activity of this modular chaperone has been attributed to a core chaperone module, with only minor importance assigned to the two SurA peptidyl-prolyl isomerase (PPIase) domains. In this work, we used synthetic phenotypes and covalent tethering to demonstrate that the activity of SurA is regulated by its PPIase domains and, furthermore, that its activity is correlated with the conformational state of the chaperone. When combined with mutations in the β-barrel assembly machine (BAM), SurA mutations resulting in deletion of the second parvulin domain (P2) inhibit OMP assembly, suggesting that P2 is involved in the regulation of SurA. The first parvulin domain (P1) potentiates this autoinhibition, as mutations that covalently tether the P1 domain to the core chaperone module severely impair OMP assembly. Furthermore, these inhibitory mutations negate the suppression of and biochemically stabilize the protein specified by a well-characterized gain-of-function mutation in P1, demonstrating that SurA cycles between distinct conformational and functional states during the OMP assembly process.IMPORTANCEThis work reveals the reversible autoinhibition of the SurA chaperone imposed by a heretofore underappreciated parvulin domain. Many β-barrel-associated outer membrane (OM) virulence factors, including the P-pilus and type I fimbriae, rely on SurA for proper assembly; thus, a mechanistic understanding of SurA function and inhibition may facilitate antibiotic intervention against Gram-negative pathogens, such as uropathogenicEscherichia coli,E. coliO157:H7,Shigella, andSalmonella. In addition, SurA is important for the assembly of critical OM biogenesis factors, such as the lipopolysaccharide (LPS) transport machine, suggesting that specific targeting of SurA may provide a useful means to subvert the OM barrier.

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Linking Engineered Gene Circuit Kinetic Modeling to Cellulose Biosynthesis Prediction in Escherichia coli: Toward Bioprocessing of Microbial Cell Factories

Industrial & Engineering Chemistry Research ◽

10.1021/acs.iecr.9b05847 ◽

2020 ◽

Vol 59 (10) ◽

pp. 4659-4669

Author(s):

Gizem Buldum ◽

Argyro Tsipa ◽

Athanasios Mantalaris

Keyword(s):

Escherichia Coli ◽

Kinetic Modeling ◽

Microbial Cell ◽

Cellulose Biosynthesis ◽

Gene Circuit ◽

Microbial Cell Factories ◽

Cell Factories

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Competence ofCorynebacterium glutamicumas a host for the production of type I polyketides

10.1101/622399 ◽

2019 ◽

Author(s):

Nicolai Kallscheuer ◽

Hirokazu Kage ◽

Lars Milke ◽

Markus Nett ◽

Jan Marienhagen

Keyword(s):

Enzymatic Activities ◽

Microbial Cell ◽

Cell Factory ◽

Type I ◽

Microbial Cell Factory ◽

Acetyl Coa ◽

Microbial Cell Factories ◽

Cell Factories ◽

C Terminus ◽

Malonyl Coa

AbstractType I polyketide synthases (PKSs) are large multi-domain proteins converting simple acyl-CoA thioesters such as acetyl-CoA and malonyl-CoA to a large diversity of biotechnologically interesting molecules. Such multi-step reaction cascades are of particular interest for applications in engineered microbial cell factories, as the introduction of a single protein with many enzymatic activities does not require balancing of several individual enzymatic activities. However, functional introduction of type I PKSs into heterologous hosts is very challenging as the large polypeptide chains often do not fold properly. In addition, PKS usually require post-translational activation by dedicated 4’-phosphopantetheinyl transferases (PPTases). Here, we introduce an engineeredCorynebacterium glutamicumstrain as a novel microbial cell factory for type I PKS-derived products. Suitability ofC. glutamicumfor polyketide synthesis could be demonstrated by the functional introduction of the 6-methylsalicylic acid synthase ChlB1 fromStreptomyces antibioticus. Challenges related to protein folding could be overcome by translation fusion of ChlB1Sato the C-terminus of the maltose-binding protein MalE fromEscherichia coli. Surprisingly, ChlB1Sawas also active in absence of a heterologous PPTase, which finally led to the discovery that the endogenous PPTase PptACgofC. glutamicumcan also activate ChlB1Sa. The best strain, engineered to provide increased levels of acetyl-CoA and malonyl-CoA, accumulated up to 41 mg/L (0.27 mM) 6-methylsalicylic acid within 48 h of cultivation. Further experiments showed that PptACgofC. glutamicumcan also activate nonribosomal peptide synthetases (NRPSs), renderingC. glutamicuma promising microbial cell factory for the production of several fine chemicals and medicinal drugs.

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