scholarly journals Interactions of Bacillus subtilis Basement Spore Coat Layer Proteins

2021 ◽  
Vol 9 (2) ◽  
pp. 285
Author(s):  
Daniela Krajčíková ◽  
Veronika Bugárová ◽  
Imrich Barák

Bacillus subtilis endospores are exceptionally resistant cells encircled by two protective layers: a petidoglycan layer, termed the cortex, and the spore coat, a proteinaceous layer. The formation of both structures depends upon the proper assembly of a basement coat layer, which is composed of two proteins, SpoIVA and SpoVM. The present work examines the interactions of SpoIVA and SpoVM with coat proteins recruited to the spore surface during the early stages of coat assembly. We showed that the alanine racemase YncD associates with two morphogenetic proteins, SpoIVA and CotE. Mutant spores lacking the yncD gene were less resistant against wet heat and germinated to a greater extent than wild-type spores in the presence of micromolar concentrations of l-alanine. In seeking a link between the coat and cortex formation, we investigated the interactions between SpoVM and SpoIVA and the proteins essential for cortex synthesis and found that SpoVM interacts with a penicillin-binding protein, SpoVD, and we also demonstrated that SpoVM is crucial for the proper localization of SpoVD. This study shows that direct contacts between coat morphogenetic proteins with a complex of cortex-synthesizing proteins could be one of the tools by which bacteria couple cortex and coat formation.

1998 ◽  
Vol 180 (9) ◽  
pp. 2285-2291 ◽  
Author(s):  
Adriano O. Henriques ◽  
Lawrence R. Melsen ◽  
Charles P. Moran

ABSTRACT Endospores of Bacillus subtilis are enclosed in a proteinaceous coat which can be differentiated into a thick, striated outer layer and a thinner, lamellar inner layer. We found that the N-terminal sequence of a 25-kDa protein present in a preparation of spore coat proteins matched that of the Mn-dependent superoxide dismutase (SOD) encoded by the sodA locus.sodA is transcribed throughout the growth and sporulation of a wild-type strain and is responsible for the SOD activity detected in total cell extracts prepared from B. subtilis. Disruption of the sodA locus produced a mutant that lacked any detectable SOD activity during vegetative growth and sporulation. The sodA mutant was not impaired in the ability to form heat- or lysozyme-resistant spores. However, examination of the coat layers of sodA mutant spores revealed increased extractability of the tyrosine-rich outer coat protein CotG. We showed that this condition was not accompanied by augmented transcription of the cotG gene in sporulating cells of the sodA mutant. We conclude that SodA is required for the assembly of CotG into the insoluble matrix of the spore and suggest that CotG is covalently cross-linked into the insoluble matrix by an oxidative reaction dependent on SodA. Ultrastructural analysis revealed that the inner coat formed by a sodA mutant was incomplete. Moreover, the outer coat lacked the characteristic striated appearance of wild-type spores, a pattern that was accentuated in acotG mutant. These observations suggest that the SodA-dependent formation of the insoluble matrix containing CotG is largely responsible for the striated appearance of this coat layer.


1999 ◽  
Vol 63 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Adam Driks

SUMMARY In response to starvation, bacilli and clostridia undergo a specialized program of development that results in the production of a highly resistant dormant cell type known as the spore. A proteinacious shell, called the coat, encases the spore and plays a major role in spore survival. The coat is composed of over 25 polypeptide species, organized into several morphologically distinct layers. The mechanisms that guide coat assembly have been largely unknown until recently. We now know that proper formation of the coat relies on the genetic program that guides the synthesis of spore components during development as well as on morphogenetic proteins dedicated to coat assembly. Over 20 structural and morphogenetic genes have been cloned. In this review, we consider the contributions of the known coat and morphogenetic proteins to coat function and assembly. We present a model that describes how morphogenetic proteins direct coat assembly to the specific subcellular site of the nascent spore surface and how they establish the coat layers. We also discuss the importance of posttranslational processing of coat proteins in coat morphogenesis. Finally, we review some of the major outstanding questions in the field.


2000 ◽  
Vol 66 (2) ◽  
pp. 620-626 ◽  
Author(s):  
Paul J. Riesenman ◽  
Wayne L. Nicholson

ABSTRACT Spores of Bacillus subtilis possess a thick protein coat that consists of an electron-dense outer coat layer and a lamellalike inner coat layer. The spore coat has been shown to confer resistance to lysozyme and other sporicidal substances. In this study, spore coat-defective mutants of B. subtilis (containing thegerE36 and/or cotE::cat mutation) were used to study the relative contributions of spore coat layers to spore resistance to hydrogen peroxide (H2O2) and various artificial and solar UV treatments. Spores of strains carrying mutations in gerE and/or cotE were very sensitive to lysozyme and to 5% H2O2, as were chemically decoated spores of the wild-type parental strain. Spores of all coat-defective strains were as resistant to 254-nm UV-C radiation as wild-type spores were. Spores possessing thegerE36 mutation were significantly more sensitive to artificial UV-B and solar UV radiation than wild-type spores were. In contrast, spores of strains possessing thecotE::cat mutation were significantly more resistant to all of the UV treatments used than wild-type spores were. Spores of strains carrying both the gerE36 andcotE::cat mutations behaved likegerE36 mutant spores. Our results indicate that the spore coat, particularly the inner coat layer, plays a role in spore resistance to environmentally relevant UV wavelengths.


2013 ◽  
Vol 62 (9) ◽  
pp. 1379-1385 ◽  
Author(s):  
Alessandro Negri ◽  
Wojciech Potocki ◽  
Adam Iwanicki ◽  
Michał Obuchowski ◽  
Krzysztof Hinc

The endospores of Bacillus subtilis can serve as a tool for surface presentation of heterologous proteins. The unique properties of the spore protective layers make them perfect vehicles for orally administered vaccines. In this study, we successfully displayed a fragment of Clostridium difficile FliD protein on the surface of B. subtilis spores using the CotB, CotC, CotG and CotZ spore coat proteins. The presence of the fusion proteins in the spore coat was verified by Western blotting and immunofluorescence microscopy. The amount of recombinant proteins was assessed by a dot-blot technique. C. difficile is one of the most common infectious agents in nosocomial infections and is especially associated with antibiotic therapies. FliD is a flagellar cap protein of C. difficile and is known to be one of the immunogenic surface antigens of this bacterium. Therefore, its use in vaccine formulations gives a good perspective for successful immunization with a FliD-based vaccine. The recombinant spores presented here may be good candidates for C. difficile oral vaccines.


2004 ◽  
Vol 186 (4) ◽  
pp. 1129-1135 ◽  
Author(s):  
Rachele Isticato ◽  
Giovanni Esposito ◽  
Rita Zilhão ◽  
Sofia Nolasco ◽  
Giuseppina Cangiano ◽  
...  

ABSTRACT We report evidence that the CotC polypeptide, a previously identified component of the Bacillus subtilis spore coat, is assembled into at least four distinct forms. Two of these, having molecular masses of 12 and 21 kDa, appeared 8 h after the onset of sporulation and were probably assembled on the forming spore immediately after their synthesis, since no accumulation of either of them was detected in the mother cell compartment, where their synthesis occurs. The other two components, 12.5 and 30 kDa, were generated 2 h later and were probably the products of posttranslational modifications of the two early forms occurring directly on the coat surface during spore maturation. None of the CotC forms was found either on the spore coat or in the mother cell compartment of a cotH mutant. This indicates that CotH serves a dual role of stabilizing the early forms of CotC and promoting the assembly of both early and late forms on the spore surface.


2014 ◽  
Vol 25 (10) ◽  
pp. 1549-1559 ◽  
Author(s):  
Kana Fukunishi ◽  
Kana Miyakubi ◽  
Mitsuko Hatanaka ◽  
Natsumi Otsuru ◽  
Aiko Hirata ◽  
...  

The spore is a dormant cell that is resistant to various environmental stresses. As compared with the vegetative cell wall, the spore wall has a more extensive structure that confers resistance on spores. In the fission yeast Schizosaccharomyces pombe, the polysaccharides glucan and chitosan are major components of the spore wall; however, the structure of the spore surface remains unknown. We identify the spore coat protein Isp3/Meu4. The isp3 disruptant is viable and executes meiotic nuclear divisions as efficiently as the wild type, but isp3∆ spores show decreased tolerance to heat, digestive enzymes, and ethanol. Electron microscopy shows that an electron-dense layer is formed at the outermost region of the wild-type spore wall. This layer is not observed in isp3∆ spores. Furthermore, Isp3 is abundantly detected in this layer by immunoelectron microscopy. Thus Isp3 constitutes the spore coat, thereby conferring resistance to various environmental stresses.


2000 ◽  
Vol 192 (1) ◽  
pp. 33-38 ◽  
Author(s):  
Hiromu Takamatsu ◽  
Atsuo Imamura ◽  
Takeko Kodama ◽  
Kei Asai ◽  
Naotake Ogasawara ◽  
...  

1998 ◽  
Vol 180 (24) ◽  
pp. 6493-6502 ◽  
Author(s):  
Thomas Murray ◽  
David L. Popham ◽  
Christine B. Pearson ◽  
Arthur R. Hand ◽  
Peter Setlow

ABSTRACT The loss of Bacillus subtilis penicillin-binding protein (PBP) 2a, encoded by pbpA, was previously shown to slow spore outgrowth and result in an increased diameter of the outgrowing spore. Further analyses to define the defect inpbpA spore outgrowth have shown that (i) outgrowingpbpA spores exhibited only a slight defect in the rate of peptidoglycan (PG) synthesis compared to wild-type spores, but PG turnover was significantly slowed during outgrowth of pbpAspores; (ii) there was no difference in the location of PG synthesis in outgrowing wild-type and pbpA spores once cell elongation had been initiated; (iii) outgrowth and elongation of pbpAspores were dramatically affected by the levels of monovalent or divalent cations in the medium; (iv) there was a partial redundancy of function between PBP2a and PBP1 or -4 during spore outgrowth; and (v) there was no difference in the structure of PG from outgrowing wild-type spores or spores lacking PBP2a or PBP2a and -4; but also (vi) PG from outgrowing spores lacking PBP1 and -2a had transiently decreased cross-linking compared to PG from outgrowing wild-type spores, possibly due to the loss of transpeptidase activity.


2002 ◽  
Vol 184 (4) ◽  
pp. 1219-1224 ◽  
Author(s):  
Irina Bagyan ◽  
Peter Setlow

ABSTRACT The enzyme CwlJ is involved in the depolymerization of cortex peptidoglycan during germination of spores of Bacillus subtilis. CwlJ with a C-terminal His tag was functional and was extracted from spores by procedures that remove spore coat proteins. However, this CwlJ was not extracted from disrupted spores by dilute buffer, high salt concentrations, Triton X-100, Ca2+-dipicolinic acid, dithiothreitol, or peptidoglycan digestion, disappeared during spore germination, and was not present in cotE spores in which the spore coat is aberrant. These findings indicate the following: (i) the reason decoated and cotE spores germinate poorly with dipicolinic acid is the absence of CwlJ from these spores; and (ii) CwlJ is located in the spore coat, presumably tightly associated with one or more other coat proteins.


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