title: Intermediatry steps in Acetobacter xylinum cellulose synthesis: studies with whole cells and cell-free preparations of the wild type and a celluloseless mutant.
abstract: Intermediatry steps in cellulose synthesis in Acetobacter xylinum were studied with resting cells and particulate-membranous preparations of the wild-type strain and of a celluloseless mutant. Exogenously supplied [1-14C]glucose was rapidly converted by resting cells of both types into glucose 6-phosphate, glucose 1-phosphate, and uridine glucose 5'-diphosphate (UDP)-glucose and incorporated into lipid-, water-, and alkali-soluble cellular fractions. The decrease in the level of labeled hexose-phosphates and UDP-glucose upon depletion of the exogenous substrate was accounted for by a continuous incorporation of [14C]glucose into cellulose in the wild type and into the above-mentioned cellular components in the mutant. [14C]glucose retained in the alkali- and water-soluble fractions of pulse-labeled wild-type cells was quantitatively chased into cellulose. Sonic extracts of both strains catalyzed the transfer of glucose from UDP-glucose into lipid-, water-, and alkali-soluble materials, as well as into an alkali-insoluble cellulosic beta-1,4-glucan. The results strongly support the sequence glucose leads to glucose 6-phosphate leads to glucose 1-phosphate leads to UDP-glucose leads to cellulose and indicate that lipid- and protein-linked cellodextrins may function as intermediates between UDP-glucose and cellulose in A. xylinum.
mesh_terms: D002474:Cell-Free System; D002482:Cellulose / Q000096:biosynthesis*; D041822:Gluconacetobacter xylinus / Q000235:genetics / Q000378:metabolism*; D005958:Glucosephosphates / Q000378:metabolism; D009154:Mutation; D014532:Uridine Diphosphate Glucose / Q000378:metabolism
chemical_list: D005958:Glucosephosphates; D002482:Cellulose; D014532:Uridine Diphosphate Glucose