Scanning electron microscopic delineation of bacterial surface topology using cationized ferritin

Lamed, Raphael; Naimark, Jenny; Morgenstern, Ely; Bayer, Edward A.

doi:10.1016/0167-7012(87)90045-5

Cited by 33 publications

(22 citation statements)

References 11 publications

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“…Altogether, including the resident ScaA enzyme, 96 different enzyme molecules can theoretically be incorporated into each A. cellulolyticus cellulosome. The intricate nature of the putative supramolecular complex is consistent with the exceptionally elaborate cell surface architecture of this bacterium (13,34,35). The central factor contributing to the enhanced amplification of the A. cellulolyticus system is the ScaB adaptor protein.…”

Section: Vol 185 2003mentioning

confidence: 53%

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The Cellulosome System of Acetivibrio cellulolyticus Includes a Novel Type of Adaptor Protein and a Cell Surface Anchoring Protein

Gao

Ding

et al. 2003

J Bacteriol

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The microbial degradation of cellulose is one of the most important processes on Earth, and it affects the human condition in many direct and indirect ways. If it did not occur, there would be an inexhaustible accumulation of plant cell refuse, and herbivorous life forms would largely vanish.The multienzyme cellulosome complex is a major mechanism by which some cellulolytic bacteria efficiently degrade cellulose and related plant cell wall polysaccharides (2,4,5,8,9,18,20,32,58,59). To date, cellulosomes have been found in several strains of anaerobic bacteria and fungi obtained from very different types of ecosystems. The first cellulosome was discovered in studies on the anaerobic thermophile Clostridium thermocellum (3,36,37). The cellulosome system of this organism consists of a variety of different enzymes bound to a noncatalytic scaffoldin subunit, which can, in turn, bind to one of several cell surface anchoring proteins. In this organism, both the attachment of the enzymes to the scaffoldin and the attachment of the scaffoldin to the anchoring proteins are accomplished by a special kind of protein-protein interaction, the cohesin-dockerin interaction. In this context, the enzyme subunits include a dockerin domain, and the scaffoldin contains multiple copies of cohesin modules for collective incorporation into the complex. The scaffoldin subunit itself harbors a single dockerin variant that interacts selectively with corresponding cohesin variants on the anchoring proteins. In C. thermocellum, the primary scaffoldin is trifunctional in that it also contains (in addition to the cohesins and dockerin) a substrate-targeting cellulose-binding domain (CBD). The anchoring proteins are bifunctional; in addition to the cohesins, they have another type of domain, the S-layer homology domain (SLH), which is known to bind strongly to the cell surface (12,40). Thus, the sequential cohesin-dockerin-mediated set of interactions among the enzymes, scaffoldin, and anchoring

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Section: Vol 185 2003mentioning

confidence: 53%

“…The cellulosome-producing, anaerobic mesophile Acetivibrio cellulolyticus, for example, is known both for its efficient degradation of crystalline cellulose and for its particularly elaborate cell surface ultrastructure (13,31,34,35,57). A novel scaffoldin (CipV) of this bacterium has recently been described and sequenced (15).…”

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confidence: 99%

The Cellulosome System of Acetivibrio cellulolyticus Includes a Novel Type of Adaptor Protein and a Cell Surface Anchoring Protein

Gao

Ding

et al. 2003

J Bacteriol

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“…Cells were treated with cationized ferritin prior to examination by electron microscopy as described previously (30,31).…”

Section: Growth Of a Cellulolyticus And Isolation Of Extracellular Pmentioning

confidence: 99%

A Novel Acetivibrio cellulolyticus Anchoring Scaffoldin That Bears Divergent Cohesins

Barak

Kenig

et al. 2004

J Bacteriol

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Sequencing of a cellulosome-integrating gene cluster in Acetivibrio cellulolyticus was completed. The cluster contains four tandem scaffoldin genes (scaA, scaB, scaC, and scaD) bounded upstream and downstream, respectively, by a presumed cellobiose phosphorylase and a nucleotide methylase. The sequences and properties of scaA, scaB, and scaC were reported previously, and those of scaD are reported here. The scaD gene encodes an 852-residue polypeptide that includes a signal peptide, three cohesins, and a C-terminal S-layer homology (SLH) module. The calculated molecular weight of the mature ScaD is 88,960; a 67-residue linker segment separates cohesins 1 and 2, and two ϳ30-residue linkers separate cohesin 2 from 3 and cohesin 3 from the SLH module. The presence of an SLH module in ScaD indicates its role as an anchoring protein. The first two ScaD cohesins can be classified as type II, similar to the four cohesins of ScaB. Surprisingly, the third ScaD cohesin belongs to the type I cohesins, like the seven ScaA cohesins. ScaD is the first scaffoldin to be described that contains divergent types of cohesins as integral parts of the polypeptide chain. The recognition properties among selected recombinant cohesins and dockerins from the different scaffoldins of the gene cluster were investigated by affinity blotting. The results indicated that the divergent types of ScaD cohesins also differ in their preference of dockerins. ScaD thus plays a dual role, both as a primary scaffoldin, capable of direct incorporation of a single dockerin-borne enzyme, and as a secondary scaffoldin that anchors the major primary scaffoldin, ScaA and its complement of enzymes to the cell surface.Cellulosomes are multienzyme complexes that are designed to efficiently degrade cellulose and related plant cell wall polysaccharides (5-10, 18-20, 22, 28, 51, 52). Bacterial cellulosomes are organized by means of a special type of subunit, the scaffoldin, which is comprised of an array of cohesin modules. The cohesin interacts selectively and tenaciously with a complementary type of domain, the dockerin, which is borne by each of the cellulosomal enzyme subunits. The integrity of the complex is thus maintained by the cohesin-dockerin interaction (4).In Clostridium thermocellum, the first cellulosome to have been described, the scaffoldin gene product (CipA) is located in a gene cluster (24) which also includes a series of genes that encode cohesin-containing anchoring proteins downstream of CipA. These anchoring proteins contain one or more cohesins and a C-terminal S-layer homology (SLH) module that mediates attachment to the cell surface (21). In contrast to the arrangement of the gene cluster in C. thermocellum, for other cellulosome-producing species, such as Clostridium cellulolyticum and Clostridium cellulovorans, gene clusters that comprise a series of genes coding for cellulosomal (dockerin-containing) enzymes instead of anchoring proteins have been described (2,11,19,53). The difference between the scaffoldins of the latter bacteria and...

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“…Some studies have examined the cellulomicroscopy observations it was suggested that since R. albus lytic and xylanolytic enzymes produced by R. albus (Wood cells do not closely adhere to the digested tissue, adhesion is et al. 1982;Forsberg and Cheng 1990;White et al 1993).…”

Section: Introductionmentioning

confidence: 99%

“…Two low molecular weight cellulose anases cloned from R. albus was studied (Romaniec et al binding proteins that might be involved in adhesion to cell-1989;Poole et al 1990;Gregg et al 1993;White et al 1993).…”

Section: Introductionmentioning

confidence: 99%

An adhesion-defective mutant of Ruminococcus albus SY3 is impaired in its capability to degrade cellulose

Miron

Morag

Lamed

et al. 1998

Journal of Applied Microbiology

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An adhesion‐defective mutant of Ruminococcus albus SY3 was isolated by a subtractive enrichment procedure, which involved repetitive adsorption of cellobiose‐grown cells to cellulose. The growth characteristics of the mutant were compared with those of the wild type. Like the wild‐type cells, the mutant was capable of growing on soluble substrates, i.e. cellobiose and xylan. However, in contrast to the wild type strain, the mutant was impaired in its capacity to utilize insoluble substrates, e.g. crystalline cellulose, acid‐swollen cellulose or alfalfa cell walls. Scanning electron microscopy revealed protuberance‐like surface structures on the wild‐type strain which were absent on the mutant. The levels of endoglucanase and xylanase enzymatic activities released into the extracellular culture fluid were higher in the wild type compared to the mutant. However, Avicelase activity was not detected in the extracellular culture fluid of either strains when grown on cellobiose.

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Scanning electron microscopic delineation of bacterial surface topology using cationized ferritin

Cited by 33 publications

References 11 publications

The Cellulosome System of Acetivibrio cellulolyticus Includes a Novel Type of Adaptor Protein and a Cell Surface Anchoring Protein

The Cellulosome System of Acetivibrio cellulolyticus Includes a Novel Type of Adaptor Protein and a Cell Surface Anchoring Protein

A Novel Acetivibrio cellulolyticus Anchoring Scaffoldin That Bears Divergent Cohesins

An adhesion-defective mutant of Ruminococcus albus SY3 is impaired in its capability to degrade cellulose

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