scholarly journals Continuous, Topologically Guided Protein Crystallization Controls Bacterial Surface Layer Self-Assembly

2019 ◽  
Author(s):  
Colin J. Comerci ◽  
Jonathan Herrmann ◽  
Joshua Yoon ◽  
Fatemeh Jabbarpour ◽  
Xiaofeng Zhou ◽  
...  
Keyword(s):  
Surface Layer ◽  
Cell Surface ◽  
Self Assembly ◽  
Cell Envelope ◽  
Protein Crystallization ◽  
Bacterial Surface ◽  
Cell Surface Structures ◽  
Complicated Topology ◽  
Layer Assembly

AbstractBacteria assemble the cell envelope using localized enzymes to account for growth and division of a topologically complicated surface1–3. However, a regulatory pathway has not been identified for assembly and maintenance of the surface layer (S-layer), a 2D crystalline protein coat surrounding the curved 3D surface of a variety of bacteria4,5. By specifically labeling, imaging, and tracking native and purified RsaA, the S-layer protein (SLP) fromC. crescentus, we show that protein self-assembly alone is sufficient to assemble and maintain the S-layerin vivo. By monitoring the location of newly produced S-layer on the surface of living bacteria, we find that S-layer assembly occurs independently of the site of RsaA secretion and that localized production of new cell wall surface area alone is insufficient to explain S-layer assembly patterns. When the cell surface is devoid of a pre-existing S-layer, the location of S-layer assembly depends on the nucleation characteristics of SLP crystals, which grow by capturing RsaA molecules freely diffusing on the outer bacterial surface. Based on these observations, we propose a model of S-layer assembly whereby RsaA monomers are secreted randomly and diffuse on the lipopolysaccharide (LPS) outer membrane until incorporated into growing 2D S-layer crystals. The complicated topology of the cell surface enables formation of defects, gaps, and grain boundaries within the S-layer lattice, thereby guiding the location of S-layer assembly without enzymatic assistance. This unsupervised mechanism poses unique challenges and advantages for designing treatments targeting cell surface structures or utilizing S-layers as self-assembling macromolecular nanomaterials. As an evolutionary driver, 2D protein self-assembly rationalizes the exceptional S-layer subunit sequence and species diversity6.

scholarly journals A Bacterial Surface Layer Protein Exploits Multi-step Crystallization for Rapid Self-assembly

2019 ◽  
Author(s):  
Jonathan Herrmann ◽  
Po-Nan Li ◽  
Fatemeh Jabbarpour ◽  
Anson C. K. Chan ◽  
Ivan Rajkovic ◽  
...  
Keyword(s):  
Surface Layer ◽  
Self Assembly ◽  
Molecular Mechanisms ◽  
Protein Crystallization ◽  
Crystal Nucleation ◽  
Time Resolved ◽  
Bacterial Surface ◽  
Surface Layer Protein

AbstractSurface layers (S-layers) are crystalline protein coats surrounding microbial cells. S-layer proteins (SLPs) regulate their extracellular self-assembly by crystallizing when exposed to an environmental trigger. However, molecular mechanisms governing rapid protein crystallization in vivo or in vitro are largely unknown. Here, we demonstrate that the C. crescentus SLP readily crystallizes into sheets in vitro via a calcium-triggered multi-step assembly pathway. This pathway involves two domains serving distinct functions in assembly. The C-terminal crystallization domain forms the physiological 2D crystal lattice, but full-length protein crystallizes multiple orders of magnitude faster due to the N-terminal nucleation domain. Observing crystallization using time-resolved electron cryo-microscopy (Cryo-EM) reveals a crystalline intermediate wherein N-terminal nucleation domains exhibit motional dynamics with respect to rigid lattice-forming crystallization domains. Dynamic flexibility between the two domains rationalizes efficient S-layer crystal nucleation on the curved cellular surface. Rate enhancement of protein crystallization by a discrete nucleation domain may enable engineering of kinetically controllable self-assembling 2D macromolecular nanomaterials.Significance StatementMany microbes assemble a crystalline protein layer on their outer surface as an additional barrier and communication platform between the cell and its environment. Surface layer proteins efficiently crystallize to continuously coat the cell and this trait has been utilized to design functional macromolecular nanomaterials. Here, we report that rapid crystallization of a bacterial surface layer protein occurs through a multi-step pathway involving a crystalline intermediate. Upon calcium-binding, sequential changes occur in the structure and arrangement of the protein, which are captured by time-resolved small angle x-ray scattering and transmission electron cryo-microscopy. We demonstrate that a specific domain is responsible for enhancing the rate of self-assembly, unveiling possible evolutionary mechanisms to enhance the kinetics of 2D protein crystallization in vivo.

scholarly journals Topologically-guided continuous protein crystallization controls bacterial surface layer self-assembly

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Colin J. Comerci ◽  
Jonathan Herrmann ◽  
Joshua Yoon ◽  
Fatemeh Jabbarpour ◽  
Xiaofeng Zhou ◽  
...  
Keyword(s):  
Surface Layer ◽  
Self Assembly ◽  
Protein Crystallization ◽  
Bacterial Surface

scholarly journals A bacterial surface layer protein exploits multistep crystallization for rapid self-assembly

2019 ◽  
Vol 117 (1) ◽  
pp. 388-394 ◽  
Author(s):  
Jonathan Herrmann ◽  
Po-Nan Li ◽  
Fatemeh Jabbarpour ◽  
Anson C. K. Chan ◽  
Ivan Rajkovic ◽  
...  
Keyword(s):  
Self Assembly ◽  
Time Course ◽  
Molecular Mechanisms ◽  
Caulobacter Crescentus ◽  
Protein Crystallization ◽  
Crystal Nucleation ◽  
Bacterial Surface ◽  
Multiple Orders

Surface layers (S-layers) are crystalline protein coats surrounding microbial cells. S-layer proteins (SLPs) regulate their extracellular self-assembly by crystallizing when exposed to an environmental trigger. However, molecular mechanisms governing rapid protein crystallization in vivo or in vitro are largely unknown. Here, we demonstrate that theCaulobacter crescentusSLP readily crystallizes into sheets in vitro via a calcium-triggered multistep assembly pathway. This pathway involves 2 domains serving distinct functions in assembly. The C-terminal crystallization domain forms the physiological 2-dimensional (2D) crystal lattice, but full-length protein crystallizes multiple orders of magnitude faster due to the N-terminal nucleation domain. Observing crystallization using a time course of electron cryo-microscopy (Cryo-EM) imaging reveals a crystalline intermediate wherein N-terminal nucleation domains exhibit motional dynamics with respect to rigid lattice-forming crystallization domains. Dynamic flexibility between the 2 domains rationalizes efficient S-layer crystal nucleation on the curved cellular surface. Rate enhancement of protein crystallization by a discrete nucleation domain may enable engineering of kinetically controllable self-assembling 2D macromolecular nanomaterials.

scholarly journals Continuous, Topologically Guided Protein Crystallization Drives Self-Assembly of a Bacterial Surface Layer

2020 ◽  
Vol 118 (3) ◽  
pp. 201a-202a
Author(s):  
Colin J. Comerci ◽  
Jonathan Herrmann ◽  
Joshua Yoon ◽  
Fatemeh Jabbarpour ◽  
Xiaofeng Zhou ◽  
...  
Keyword(s):  
Surface Layer ◽  
Self Assembly ◽  
Protein Crystallization ◽  
Bacterial Surface

scholarly journals Proteoglycans contribute to the functional integrity of the glomerular endothelial cell surface layer and are regulated in diabetic kidney disease

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alina Khramova ◽  
Roberto Boi ◽  
Vincent Fridén ◽  
Anna Björnson Granqvist ◽  
Ulf Nilsson ◽  
...  
Keyword(s):  
Surface Layer ◽  
Kidney Disease ◽  
Cell Surface ◽  
Diabetic Kidney Disease ◽  
Exchange Chromatography ◽  
Diabetic Kidney ◽  
Endothelial Cell Surface ◽  
Filtration Barrier ◽  
Essential Components

AbstractAll capillary endothelia, including those of the glomeruli, have a luminal cell surface layer (ESL) consisting of glycoproteins, glycolipids, proteoglycans (PGs) and glycosaminoglycans. Previous results have demonstrated that an intact ESL is necessary for a normal filtration barrier and damage to the ESL coupled to proteinuria is seen for example in diabetic kidney disease (DKD). We used the principles of ion exchange chromatography in vivo to elute the highly negatively charged components of the ESL with a 1 M NaCl solution in rats. Ultrastructural morphology and renal function were analyzed and 17 PGs and hyaluronan were identified in the ESL. The high salt solution reduced the glomerular ESL thickness, led to albuminuria and reduced GFR. To assess the relevance of ESL in renal disease the expression of PGs in glomeruli from DKD patients in a next generation sequencing cohort was investigated. We found that seven of the homologues of the PGs identified in the ESL from rats were differently regulated in patients with DKD compared to healthy subjects. The results show that proteoglycans and glycosaminoglycans are essential components of the ESL, maintaining the permselective properties of the glomerular barrier and thus preventing proteinuria.

scholarly journals Myxococcus xanthus dif Genes Are Required for Biogenesis of Cell Surface Fibrils Essential for Social Gliding Motility

2000 ◽  
Vol 182 (20) ◽  
pp. 5793-5798 ◽  
Author(s):  
Zhaomin Yang ◽  
Xiaoyuan Ma ◽  
Leming Tong ◽  
Heidi B. Kaplan ◽  
Lawrence J. Shimkets ◽  
...  
Keyword(s):  
Cell Surface ◽  
Myxococcus Xanthus ◽  
Bacterial Chemotaxis ◽  
Type Iv Pili ◽  
Gliding Motility ◽  
Genetic Studies ◽  
Developmental Defects ◽  
Bacterial Surface ◽  
Type Iv ◽  
Cell Surface Structures

ABSTRACT Myxococcus xanthus social (S) gliding motility has been previously reported by us to require the chemotaxis homologues encoded by the dif genes. In addition, two cell surface structures, type IV pili and extracellular matrix fibrils, are also critical to M. xanthus S motility. We have demonstrated here that M. xanthus dif genes are required for the biogenesis of fibrils but not for that of type IV pili. Furthermore, the developmental defects of dif mutants can be partially rescued by the addition of isolated fibril materials. Along with the chemotaxis genes of various swarming bacteria and the pilGHIJ genes of the twitching bacteriumPseudomonas aeruginosa, the M. xanthus dif genes belong to a unique class of bacterial chemotaxis genes or homologues implicated in the biogenesis of structures required for bacterial surface locomotion. Genetic studies indicate that the dif genes are linked to theM. xanthus dsp region, a locus known to be crucial forM. xanthus fibril biogenesis and S gliding.

scholarly journals Bacillus anthracis SlaQ Promotes S-Layer Protein Assembly

2015 ◽  
Vol 197 (19) ◽  
pp. 3216-3227 ◽  
Author(s):  
Sao-Mai Nguyen-Mau ◽  
So-Young Oh ◽  
Daphne I. Schneewind ◽  
Dominique Missiakas ◽  
Olaf Schneewind
Keyword(s):  
Bacillus Anthracis ◽  
Self Assembly ◽  
Protein Assembly ◽  
Crystalline Lattice ◽  
Cell Wall Polysaccharide ◽  
Cytoplasmic Protein ◽  
Content Type ◽  
Bacterial Surface

ABSTRACTBacillus anthracisvegetative forms assemble an S-layer comprised of two S-layer proteins, Sap and EA1. A hallmark of S-layer proteins are their C-terminal crystallization domains, which assemble into a crystalline lattice once these polypeptides are deposited on the bacterial surface via association between their N-terminal S-layer homology domains and the secondary cell wall polysaccharide. Here we show thatslaQ, encoding a small cytoplasmic protein conserved among pathogenic bacilli elaborating S-layers, is required for the efficient secretion and assembly of Sap and EA1. S-layer protein precursors cosediment with SlaQ, and SlaQ appears to facilitate Sap assembly. Purified SlaQ polymerizes and when mixed with purified Sap promotes thein vitroformation of tubular S-layer structures. A model is discussed whereby SlaQ, in conjunction with S-layer secretion factors SecA2 and SlaP, promotes localized secretion and S-layer assembly inB. anthracis.IMPORTANCES-layer proteins are endowed with the propensity for self-assembly into crystalline arrays. Factors promoting S-layer protein assembly have heretofore not been reported. We identifiedBacillus anthracisSlaQ, a small cytoplasmic protein that facilitates S-layer protein assemblyin vivoandin vitro.

scholarly journals MxiM and MxiJ, Base Elements of the Mxi-Spa Type III Secretion System of Shigella, Interact with and Stabilize the MxiD Secretin in the Cell Envelope

2001 ◽  
Vol 183 (24) ◽  
pp. 6991-6998 ◽  
Author(s):  
Raymond Schuch ◽  
Anthony T. Maurelli
Keyword(s):  
Cell Surface ◽  
Type Iii Secretion ◽  
Cell Envelope ◽  
General Structure ◽  
Eukaryotic Cell ◽  
Effector Proteins ◽  
Complex Assembly ◽  
Base Element ◽  
Type Iii

ABSTRACT The type III secretion pathway is broadly distributed across many parasitic bacterial genera and serves as a mechanism for delivering effector proteins to eukaryotic cell surface and cytosolic targets. While the effectors, as well as the host responses elicited, differ among type III systems, they all utilize a conserved set of 9 to 11 proteins that together form a bacterial envelope-associated secretory organelle or needle complex. The general structure of the needle complex consists of a transenvelope base containing at least three ring-forming proteins (MxiD, MxiJ, and MxiG in Shigella) that is connected to a hollow needle-like extension that projects away from the cell surface. Several studies have shown that the initial steps in needle complex assembly require interactions among the base proteins, although specific details of this process remain unknown. Here we identify a role for another base element inShigella, MxiM, in interactions with the major outer-membrane-associated ring-forming protein, MxiD. MxiM affects several features of MxiD, including its stability, envelope association, and assembly into homomultimeric structures. Interestingly, many of the effects were also elicited by the inner-membrane-associated base element, MxiJ. We confirmed that MxiM-MxiD and MxiJ-MxiD interactions occur in vivo in the cell envelope, and we present evidence that together these base elements can form a transmembrane structure which is likely an important intermediary in the process of needle complex assembly.

scholarly journals Engineered Lactococcus lactis Secreting IL-23 Receptor-Targeted REX Protein Blockers for Modulation of IL-23/Th17-Mediated Inflammation

2019 ◽  
Vol 7 (5) ◽  
pp. 152 ◽  
Author(s):  
Tina Vida Plavec ◽  
Milan Kuchař ◽  
Anja Benko ◽  
Veronika Lišková ◽  
Jiří Černý ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Cell Surface ◽  
Lactococcus Lactis ◽  
Probiotic Bacterium ◽  
Host Cells ◽  
Bacterial Surface ◽  
Cdna Sequences ◽  
Secretion Signal ◽  
Antibody Conjugate

Lactococcus lactis, a probiotic bacterium of food origin, has recently been demonstrated as a suitable strain for the production and in vivo delivery of therapeutically important proteins into the gut. We aimed to engineer recombinant L. lactis cells producing/secreting REX binding proteins that have been described as IL-23 receptor (IL-23R) blockers and IL-23R antagonists suppressing the secretion of cytokine IL-17A, a pivotal step in the T-helper Th17-mediated pro-inflammatory cascade, as well as in the development of autoimmune diseases, including inflammatory bowel disease (IBD). To reach this goal, we introduced cDNA sequences coding for REX009, REX115, and REX125 proteins into plasmid vectors carrying a Usp45 secretion signal, a FLAG tag sequence consensus, and a LysM-containing cA surface anchor (AcmA), thus allowing cell–surface peptidoglycan anchoring. These plasmids, or their non-FLAG/non-AcmA versions, were introduced into L. lactis host cells, thus generating unique recombinant L. lactis–REX strains. We demonstrate that all three REX proteins are expressed in L. lactis cells and are efficiently displayed on the bacterial surface, as tested by flow cytometry using an anti-FLAG antibody conjugate. Upon 10-fold concentration of the conditioned media, a REX125 secretory variant can be detected by Western blotting. To confirm that the FLAG/non-FLAG REX proteins displayed by L. lactis retain their binding specificity, cell-surface interactions of REX proteins with an IL-23R-IgG chimera were demonstrated by flow cytometry. In addition, statistically significant binding of secreted REX009 and REX115 proteins to bacterially produced, soluble human IL-23R was confirmed by ELISA. We conclude that REX-secreting L. lactis strains were engineered that might serve as IL-23/IL-23R blockers in an experimentally induced mouse model of colitis.

scholarly journals Crystalline S-Layer Protein Monolayers Induce Water Turbulences on the Nanometer Scale

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1147
Author(s):  
Rupert Tscheliessnig ◽  
Andreas Breitwieser ◽  
Uwe B. Sleytr ◽  
Dietmar Pum
Keyword(s):  
Cell Surface ◽  
Molecular Sieves ◽  
Cell Envelope ◽  
Functional Model ◽  
Ion Traps ◽  
Coarse Grained ◽  
Flow Profile ◽  
Natural Habitats ◽  
Bacterial Surface ◽  
Wide Range

Bacterial surface layers (S-layers) have been observed as the outermost cell envelope component in a wide range of bacteria and most archaea. They are one of the most common prokaryotic cell surface structures and cover the cells completely. It is assumed that S-layers provide selection advantages to prokaryotic cells in their natural habitats since they act as protective envelopes, as structures involved in cell adhesion and surface recognition, as molecular or ion traps, and as molecular sieves in the ultrafiltration range. In order to contribute to the question of the function of S-layers for the cell, we merged high-resolution cryo-EM and small-angle X-ray scattering datasets to build a coarse-grained functional model of the S-layer protein SbpA from Lysinibacillus sphaericus ATCC 4525. We applied the Navier–Stokes and the Poisson equations for a 2D section through the pore region in the self-assembled SbpA lattice. We calculated the flow field of water, the vorticity, the electrostatic potential, and the electric field of the coarse-grained model. From calculated local changes in the flow profile, evidence is provided that both the characteristic rigidity of the S-layer and the charge distribution determine its rheological properties. The strength of turbulence and pressure near the S-layer surface in the range of 10 to 50 nm thus support our hypothesis that the S-layer, due to its highly ordered repetitive crystalline structure, not only increases the exchange rate of metabolites but is also responsible for the remarkable antifouling properties of the cell surface. In this context, studies on the structure, assembly and function of S-layer proteins are promising for various applications in nanobiotechnology, biomimetics, biomedicine, and molecular nanotechnology.

Sign in / Sign up

Export Citation Format

Share Document