A non-modular endo-β-1,4-mannanase from Pseudomonas fluorescens subspecies cellulosa

Braithwaite, K.L.; Black, Gary W.; Hazlewood, Geoffrey P.; Ali, Bassam R.; Gilbert, Harry J.

doi:10.1042/bj3051005

Cited by 60 publications

(37 citation statements)

References 26 publications

(23 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…2). This is consistent with the utilization of plant-derived complex carbohydrates as a major growth substrate by both organisms (7,22,23,26,38) and the retention of this hydrolytic apparatus by both species during the course of evolution. The other 50% (n ϭ 77) of these predicted degradative enzymes are found among the 1,619 "unique" proteins that are predicted in the C. japonicus genome and absent from the other three related organisms (Fig.…”

Section: Vol 190 2008 Genome Sequence Of Cellvibrio Japonicus 5457supporting

confidence: 66%

“…C. japonicus has been experimentally shown to degrade all of the major plant cell wall polysaccharides, including crystalline cellulose, mannan, and xylan (7,22,23,25,26), and is a able to grow on media in which these polysaccharides are the sole carbon and energy source. Unlike the case for anaerobic plant cell wall-degrading organisms, exemplified by Clostridium thermocellum, the C. japonicus enzymes that target polysaccharides, which are integral to the plant cell wall, are fully secreted into the culture media and do not assemble into large multienzyme cellulosome-like complexes (7,22,23,26). Since the first cellulase genes from C. japonicus were cloned ϳ20 years (22) ago, numerous plant cell wall-degrading glycoside hydrolases, esterases, and lyases have been biochemically characterized (for a review, see reference 25).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Insights into Plant Cell Wall Degradation from the Genome Sequence of the Soil Bacterium Cellvibrio japonicus

et al. 2008

View full text Add to dashboard Cite

The plant cell wall, which consists of a highly complex array of interconnecting polysaccharides, is the most abundant source of organic carbon in the biosphere. Microorganisms that degrade the plant cell wall synthesize an extensive portfolio of hydrolytic enzymes that display highly complex molecular architectures. To unravel the intricate repertoire of plant cell wall-degrading enzymes synthesized by the saprophytic soil bacterium Cellvibrio japonicus, we sequenced and analyzed its genome, which predicts that the bacterium contains the complete repertoire of enzymes required to degrade plant cell wall and storage polysaccharides. Approximately one-third of these putative proteins (57) are predicted to contain carbohydrate binding modules derived from 13 of the 49 known families. Sequence analysis reveals approximately 130 predicted glycoside hydrolases that target the major structural and storage plant polysaccharides. In common with that of the colonic prokaryote Bacteroides thetaiotaomicron, the genome of C. japonicus is predicted to encode a large number of GH43 enzymes, suggesting that the extensive arabinose decorations appended to pectins and xylans may represent a major nutrient source, not just for intestinal bacteria but also for microorganisms that occupy terrestrial ecosystems. The results presented here predict that C. japonicus possesses an extensive range of glycoside hydrolases, lyases, and esterases. Most importantly, the genome of C. japonicus is remarkably similar to that of the gram-negative marine bacterium, Saccharophagus degradans 2-40 T . Approximately 50% of the predicted C. japonicus plant-degradative apparatus appears to be shared with S. degradans, consistent with the utilization of plant-derived complex carbohydrates as a major substrate by both organisms.

show abstract

Section: Vol 190 2008 Genome Sequence Of Cellvibrio Japonicus 5457supporting

confidence: 66%

mentioning

confidence: 99%

Insights into Plant Cell Wall Degradation from the Genome Sequence of the Soil Bacterium Cellvibrio japonicus

et al. 2008

View full text Add to dashboard Cite

show abstract

“…These data all point to the novel catalytic activity of CjMan26C. In contrast to all of the other GH26 ␤-mannanases characterized to date (8,22), which are endo-acting, CjMan26C is not only an exo-mannanase but is to our knowledge the first to be described that releases the disaccharide mannobiose and not mannose. By analogy to the terminology used to describe …”

Section: Cjman26c Defines a New Class Of Mannobiohydrolasementioning

confidence: 79%

The Cellvibrio japonicus Mannanase CjMan26C Displays a Unique exo-Mode of Action That Is Conferred by Subtle Changes to the Distal Region of the Active Site

Cartmell

Topakas

Ducros

et al. 2008

Journal of Biological Chemistry

View full text Add to dashboard Cite

The microbial degradation of the plant cell wall is a pivotal biological process that is of increasing industrial significance. One of the major plant structural polysaccharides is mannan, a ␤-1,4-linked D-mannose polymer, which is hydrolyzed by endoand exo-acting mannanases. The mechanisms by which the exoacting enzymes target the chain ends of mannan and how galactose decorations influence activity are poorly understood. Here we report the crystal structure and biochemical properties of CjMan26C, a Cellvibrio japonicus GH26 mannanase. The exoacting enzyme releases the disaccharide mannobiose from the nonreducing end of mannan and mannooligosaccharides, harnessing four mannose-binding subsites extending from ؊2 to ؉2. The structure of CjMan26C is very similar to that of the endo-acting C. japonicus mannanase CjMan26A. The exo-activity displayed by CjMan26C, however, reflects a subtle change in surface topography in which a four-residue extension of surface loop creates a steric block at the distal glycone ؊2 subsite. endoActivity can be introduced into enzyme variants through truncation of an aspartate side chain, a component of a surface loop, or by removing both the aspartate and its flanking residues. The structure of catalytically competent CjMan26C, in complex with a decorated manno-oligosaccharide, reveals a predominantly unhydrolyzed substrate in an approximate 1 S 5 conformation. The complex structure helps to explain how the substrate "side chain" decorations greatly reduce the activity of the enzyme; the galactose side chain at the ؊1 subsite makes polar interactions with the aglycone mannose, possibly leading to suboptimal binding and impaired leaving group departure. This report reveals how subtle differences in the loops surrounding the active site of a glycoside hydrolase can lead to a change in the mode of action of the enzyme.The plant cell wall represents the dominant source of organic carbon in the biosphere and as such supports many facets of terrestrial and marine life. Access to this valuable source of carbon is mediated by extensive microbial enzyme consortia, which generate sugars that are utilized by microbial ecosystems to the benefit of plants, mammalian herbivores, and insects. These degradative enzymes are increasingly deployed in industrial processes, and it is apparent that their use in producing second generation, lignocellulosebased, biofuels is of considerable environmental significance (1, 2). Among the major polysaccharides in softwoods and angiosperms are the mannans. These polysaccharides comprise a backbone of ␤-1,4-linked D-mannopyranose sugars (known as "mannan") or a heterogeneous combination of ␤-1,4-D-mannose and ␤-1,4-D-glucose units (termed "glucomannan"), which can be decorated with ␣-1,6-galactose side chains to yield "galactomannan" and "galactoglucomannan," respectively (3). For complete enzymatic degradation, the galactose decorations are removed by ␣-galactosidases (4, 5), whereas the internal glycosidic linkages in mannans are cleaved by endo-␤-1,4 mannanases ...

show abstract

“…Bacterial strains were found to produce carbohydrases for degradation of polysaccharides generally present in the cell wall of Tetraselmis (glucans, galactans, galactomannans and pectins), whereas no such utilisation was observed for other wall substrates, such as cellulose, arabinoxylan and rhamnogalacturonan. The production of carbo hy dra ses such as pectinases, glucanases, galactan ases and mannanases from various species of Pseudomonas and Acinetobacter has also been re ported in earlier studies (Katohda et al 1979, Simonson et al 1982, Braithwaite et al 1995, Tita poka et al 2008, Aboaba 2009, Zheng et al 2011. Since Acine to bacter sp.…”

Section: Discussionmentioning

confidence: 99%

Carbohydrate-degrading bacteria closely associated with Tetraselmis indica: influence on algal growth

Arora¹,

Anil²,

Delany³

et al. 2012

Aquat. Biol.

View full text Add to dashboard Cite

In the present study, we examined the interactions between the algal species Tetraselmis indica and strains of bacteria with which it is closely associated. Three bacterial strains were isolated and sequence analysis of the 16S rDNA indicated that the organisms belong to the genera Pseudomonas, Acinetobacter and Ruegeria. Morphologies of the bacterial strains were studied using epifluorescence microscopy and scanning electron microscopy. Reassociation experiments were conducted with axenic cultures inoculated with the 3 bacterial strains in concentrations comparable to natural conditions, and the effect of each bacterial population on the growth of T. indica was determined. T. indica exhibited differential growth with the various bacterial cultures, and in particular Acinetobacter sp. was observed to promote growth of the algae. These experiments revealed that microbes associated with the alga differentially influence algal growth dynamics. Bacterial presence on the cast-off cell wall products of the alga suggested the likely utilisation of algal cell wall by bacteria. The bacterial strains were tested for carbohydrate metabolism using various sugars and screened for carbohydrase activity. Bacterial strains were found to produce carbohydrases for degradation of polysaccharides generally present in the cell wall of Tetraselmis (glucans, galactans, galactomannans and pectins), whereas no such utilisation was observed for other wall substrates (such as cellulose, arabinoxylan, rhamnogalacturonan). Pseudomonas sp. and Acineto bacter sp. showed carbohydrase activity with glucans, galactans, galactomannans and pectin, whereas Ruegeria sp. showed much less carbohydrase activity and only with pectin. The carbohydrate utilisation studies using artificial substrates suggested the potential utilisation of cast-off algal cell wall products.

show abstract

A non-modular endo-β-1,4-mannanase from Pseudomonas fluorescens subspecies cellulosa

Cited by 60 publications

References 26 publications

Insights into Plant Cell Wall Degradation from the Genome Sequence of the Soil Bacterium Cellvibrio japonicus

Insights into Plant Cell Wall Degradation from the Genome Sequence of the Soil Bacterium Cellvibrio japonicus

The Cellvibrio japonicus Mannanase CjMan26C Displays a Unique exo-Mode of Action That Is Conferred by Subtle Changes to the Distal Region of the Active Site

Carbohydrate-degrading bacteria closely associated with Tetraselmis indica: influence on algal growth

Contact Info

Product

Resources

About