Cellulose biosynthesis and function in bacteria

“xylinum does not engage in glycogen production (73), which in bacteria typically requires ADP-Glc (103).”

“1, Cellulose synthase (2, 115); 2, glucose oxidase (60); 3, glucose permease; 4, gluconate permease (19); 5, UDPG-pyrophosphorylase (UTP) (143); 6, glucokinase (ATP) (19); 7, gluconokinase (ATP); 8, phosphogluco-”

“The plant cell wall is a semipermeable composite tissue of high species variability (34) and is compounded from layered deposits of cellulose fibrils in which are embedded more amorphous polymers, including neutral and acidic polysaccharides, glycoproteins, and waxy aromatic substances (40).”

“Both the width of microfibrils and the parallel glucan chain arrangement within them may be accounted for by current models of cellulose biogenesis (101, 105, 112, 130) in which the sites of glucose polymerization are situated in clusters according to two basic degrees of organization.”

“On the basis of PDE-A and cellulose synthase reaction data (Table 1), these molecules would not be expected to be functionally distinct from c-di-GMP, and it is not clear whether they would be formed within the cell, considering the much higher concentration of GTP than dGTP (25).”

“This is in contradiction to previously proposed models in which intramembranous particles that were revealed by freeze-etching of the cell envelope were taken to indicate that cellulose synthase is located in the outer membrane (28, 38).”

“Both the width of microfibrils and the parallel glucan chain arrangement within them may be accounted for by current models of cellulose biogenesis (101, 105, 112, 130) in which the sites of glucose polymerization are situated in clusters according to two basic degrees of organization.”

“xylinum does not engage in glycogen production (73), which in bacteria typically requires ADP-Glc (103).”

“Such Celmutants may be isolated and may prove to be stable and nonreverting over the course of years of cultivation (123).”

“Low-molecularweight, cell-impermeable compounds, such as the fluorescent brighteners Calcofluor White (Tinopal) and Congo red, or the water-soluble, high-molecular-weight cellulose derivative carboxymethyl cellulose avidly binds to ,B-glucans in a definable, reversible manner (27, 64, 65).”

“Cellulose is also not completely necessary for bacterial virulence, because transposon mutants deficient in cellulose synthesis retain their pathogenecity (98).”

“orderly assembly of the fibril structure on all levels (16).”

“sumed to engage in lateral movement within the cytoplasmic membrane, which is channeled in appropriate directions as a result of the underlying microtubular cytoskeleton (61, 69, 93, 111, 130).”

“xylinum to produce cellulose has not reached full expression, although reports on this process, as well as on industrial production of other bacterial exopolysaccharides (67, 118), indicate that the ultimate potential of bacterial cells”

“The new techniques recently applied to demonstrating the polarity of isolated cellulose I microfibrils (35, 88) may ultimately be used in determining the direction of polyglucan chain growth.”

“In analogies inspired by electron-microscopic images of plant cell wall replicas (106), the structural role of cellulose has been likened to that of the nylon strands of fiber glass or to the supporting rods within reinforced concrete.”

“An early step in the infection process is the site-specific attachment of the bacteria to the plant host cells (92).”

“The cellulosic product of this organism has been characterized on the basis of enzymatic analysis (127) and infrared spectroscopy (102, 127); X-ray diffraction analysis has revealed a pattern characteristic of cellulose I (102).”

“xylinum strains and Agrobacterium tumefaciens (5).”

“These last two genera are closely related in other respects, including on the DNA level (70).”

“mutase (60); 9, glucose-6-P1-dehydrogenase (NAD); 9a, glucose-6-Pi-dehydrogenase (NADP) (17); 10, 6-phosphogluconate dehydrogenase (NAD); 10a, 6-phosphogluconate dehydrogenase (NADP); 11, phosphoglucoisomerase; 12, phosphoribulose epimerase; 13, phosphoribulose isomerase; 14, transketolase; 15, transaldolase (60); 16,…”

“Both the width of microfibrils and the parallel glucan chain arrangement within them may be accounted for by current models of cellulose biogenesis (101, 105, 112, 130) in which the sites of glucose polymerization are situated in clusters according to two basic degrees of organization.”

“Among the several factors defined for the two-step attachment process, the first phase involves a Ca2'-dependent soluble cell surface protein (rhicadhesin), which is also present in Agrobacterium species (128, 129).”

“Perhaps the most unifying feature, recognized now for many years, is at the cytostructural level (26, 44, 62).”

“lized forms has been characterized enzymatically and chemically as a ,B-1,4-linked glucan (2, 3, 29).”

“Such a processive mechanism has also been proposed for yeast chitin synthase (82), although this enzyme, as well as the 1-1,3-glucan synthase of plants (68), may be released from the product-entrapped state by relatively mild treatments.”

“In fast-growing rhizobia, many essential nodulation genes, including the genes coding for host specificity, are located on a large plasmid, the so-called Sym plasmid (83).”

“xylinum to produce cellulose has not reached full expression, although reports on this process, as well as on industrial production of other bacterial exopolysaccharides (67, 118), indicate that the ultimate potential of bacterial cells”

“based on an immobilized form of the GTP substrate (113, 114).”

“Among the several factors defined for the two-step attachment process, the first phase involves a Ca2'-dependent soluble cell surface protein (rhicadhesin), which is also present in Agrobacterium species (128, 129).”

“composed from an octasaccharide repeating unit containing glucose, galactose, and pyruvate in the ratio 7:1:1 (22, 74, 75, 158).”

“The bacterium grows and produces cellulose from a wide range of substrates (11, 72, 149, 150) and is devoid of cellulase activity (73).”

“The new techniques recently applied to demonstrating the polarity of isolated cellulose I microfibrils (35, 88) may ultimately be used in determining the direction of polyglucan chain growth.”

“electron transport chain interrupt the synthesis (121).”

“1, Cellulose synthase (2, 115); 2, glucose oxidase (60); 3, glucose permease; 4, gluconate permease (19); 5, UDPG-pyrophosphorylase (UTP) (143); 6, glucokinase (ATP) (19); 7, gluconokinase (ATP); 8, phosphogluco-”

“xylinum was confined to physiological and morphological approaches, concerned with identifying the intracellular precursors of polyglucose chains (1) or characterizing the steps in their assembly into fibrils (27, 63).”

“The resultant degree of order is sufficiently high for crystallographic analysis (23, 54); interpretation of X-ray and electron diffraction patterns suggests several polymorphic possibilities for the cellulose crystal, one of which is portrayed in Fig.”

“Although many of the unique features of this cell-free system have been confirmed in other laboratories (29, 91, 139, 143), it is only recently that investigators have apparently succeeded in their attempts to render the cellulose synthase from other organisms accessible to biochemical analysis (5, 139).”

“The conversion of hexose phosphate to cellulose is direct in the sense that it does not necessarily include intermediary cleavage of the carbon skeleton of the hexose moiety (121, 122).”

“The genes involved in cellulose synthesis and the attachment interaction have been mapped to within the same area, suggesting that there is a region of the Agrobacterium chromosome which is concerned with the plant host cell surface interaction in general (110).”

“nosarum (1 to 10 per cell) range from 5 to 6 nm in diameter and up to 10 ,um in length (126).”

“Low-molecularweight, cell-impermeable compounds, such as the fluorescent brighteners Calcofluor White (Tinopal) and Congo red, or the water-soluble, high-molecular-weight cellulose derivative carboxymethyl cellulose avidly binds to ,B-glucans in a definable, reversible manner (27, 64, 65).”

“coli have shown that UDPG-pyrophosphorylase-defective mutants lack detectable galactose (an epimer of glucose produced via UDP-Glc) in their cell walls (55) and lipopolysaccharide (134).”

“mutase (60); 9, glucose-6-P1-dehydrogenase (NAD); 9a, glucose-6-Pi-dehydrogenase (NADP) (17); 10, 6-phosphogluconate dehydrogenase (NAD); 10a, 6-phosphogluconate dehydrogenase (NADP); 11, phosphoglucoisomerase; 12, phosphoribulose epimerase; 13, phosphoribulose isomerase; 14, transketolase; 15, transaldolase (60); 16,…”

“The cellulosic nature of this intercellular cementing material, which may account for up to 18% of the total dry weight of the cells (33), is based mainly on solubility properties and digestion with a crude cellulase preparation.”

“xylinum, only one is inhibited by ATP (17).”

“Under suitable conditions (14), as much as 50% of the supplied carbon substrate may be assimilated into cellulose to produce a remarkably thick pellicle (Fig.”

“In such an analysis, however, the effect of substitutions on the overall conformation of the molecule is not taken into account; cyclic dinucleotides can adopt a variety of asymmetrical conformations in solution (24) and in the crystalline state (53); this necessarily limits many conclusions regarding the structure-fu…”

“mannose, and glucuronic acid in various proportions (41, 144).”

“In such an analysis, however, the effect of substitutions on the overall conformation of the molecule is not taken into account; cyclic dinucleotides can adopt a variety of asymmetrical conformations in solution (24) and in the crystalline state (53); this necessarily limits many conclusions regarding the structure-fu…”

“Within the cell, PP, is rapidly cleaved to yield Pi (18).”

“mutase (60); 9, glucose-6-P1-dehydrogenase (NAD); 9a, glucose-6-Pi-dehydrogenase (NADP) (17); 10, 6-phosphogluconate dehydrogenase (NAD); 10a, 6-phosphogluconate dehydrogenase (NADP); 11, phosphoglucoisomerase; 12, phosphoribulose epimerase; 13, phosphoribulose isomerase; 14, transketolase; 15, transaldolase (60); 16,…”

“1, Cellulose synthase (2, 115); 2, glucose oxidase (60); 3, glucose permease; 4, gluconate permease (19); 5, UDPG-pyrophosphorylase (UTP) (143); 6, glucokinase (ATP) (19); 7, gluconokinase (ATP); 8, phosphogluco-”

“mutase (60); 9, glucose-6-P1-dehydrogenase (NAD); 9a, glucose-6-Pi-dehydrogenase (NADP) (17); 10, 6-phosphogluconate dehydrogenase (NAD); 10a, 6-phosphogluconate dehydrogenase (NADP); 11, phosphoglucoisomerase; 12, phosphoribulose epimerase; 13, phosphoribulose isomerase; 14, transketolase; 15, transaldolase (60); 16,…”

“is synthesized simultaneously with other exopolysaccharides, including curdlan, a P-1,3-glucan which appears to contain some degree of organized tertiary structure and yields insoluble gels (86).”

“This is in contradiction to previously proposed models in which intramembranous particles that were revealed by freeze-etching of the cell envelope were taken to indicate that cellulose synthase is located in the outer membrane (28, 38).”

“The biological occurrence of terminal complexes and rosettes has been classified according to phylogenetic history, wherein the distinction is made between fixed and mobile bigenetic apparatus (27, 77, 89).”

“coli, in which the native products, known as membrane-derived oligosaccharides (MDOs), typically occur as ,8-1,6-branched derivatives in linkage to phosphoglyceride and/or succinate, as well as in membranous preparations from Agrobacterium radiobacter and Rhizobium phaseoli, in which the predominant in vivo species is…”

“mutase (60); 9, glucose-6-P1-dehydrogenase (NAD); 9a, glucose-6-Pi-dehydrogenase (NADP) (17); 10, 6-phosphogluconate dehydrogenase (NAD); 10a, 6-phosphogluconate dehydrogenase (NADP); 11, phosphoglucoisomerase; 12, phosphoribulose epimerase; 13, phosphoribulose isomerase; 14, transketolase; 15, transaldolase (60); 16,…”

“corresponding polyprenol diphosphate saccharide, which grows from the addition of galactose followed by glucosylation in a sequence of,B-1,4, ,B-1,6, and 1-1,3 bonding, as determined in vitro by using radiolabeled UDP-Glc or UDPGal as a substrate (131).”

“xylinum strains have also been observed to utilize UDPGlc in forming a high-molecular-weight P-1,2-homoglucan (117); however, such a material has been detected in only”

“occurs at a rate that is linear with respect to the cell concentration (73, 81) and, as mentioned above, is constitutive with respect to the carbon source supplied for cell FIG.”

“composed from an octasaccharide repeating unit containing glucose, galactose, and pyruvate in the ratio 7:1:1 (22, 74, 75, 158).”

“If individual ,-1,4glucan chains were synthesized in a disorganized, random fashion, the result would probably be a tangled mass in which any recognizable fibril structures contain chains associated in opposing directions or bent back upon themselves (119, 132).”

“An extensive study of this process by Benziman and colleagues showed that it is regulated by cyclic diguanylate (c-diGMP, bis(3P,5P)-cyclic diguanylic acid), a novel e¡ector molecule that consists of two cGMP moieties bound head-to-tail [31].”