ORF2 gene involves in the construction of high-order structure of bacterial cellulose.
An ORF2 gene located upstream of the cellulose synthase (bcs) operon of Acetobacter xylinum BPR2001 was disrupted and a mutant (M2-2) was constructed. In static cultivation, the parent strain produced a tough, colorless, and insoluble cellulose pellicle, whereas M2-2 culture produced a thin, yellow, and fragile pellicle. The results of X-ray diffraction and 13C solid-state NMR indicated that the product of M2-2 is a mixture of cellulose I, cellulose II, and amorphous cellulose. The cellulose I to cellulose II ratio of the mixture was evaluated from the signal areas of C6 to be about 1:2. Electron microscopy revealed that the product of M2-2 included ribbon-like cellulose and irregularly shaped particles attached to the ribbons. On the other hand, the mutant complemented with plasmid pSA-ORF2/k containing the ORF2 gene and BPR2001 produced only cellulose I. These results indicate that the ORF2 gene is involved in the production and crystallization of cellulose I microfibrils by this microorganism.
Nakai
Tomonori
T
Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.
Nishiyama
Yoshiharu
Y
Kuga
Shigenori
S
Sugano
Yasushi
Y
Shoda
Makoto
M
D000091:Acetobacter / Q000235:genetics; D002236:Carbohydrate Conformation; D002482:Cellulose / Q000737:chemistry* / Q000648:ultrastructure; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D008854:Microscopy, Electron; D014961:X-Ray Diffraction
D002482:Cellulose