produced cellulose I, cellulose II, and amorphous cellulose (25).
Together, orf2 (located downstream of cmcax) and cmcax comprise
an operon (Fig. 1A) (15, 25). In an orf2-disrupted strain,
cmcax may be normally expressed because it locates upstream of
orf2. Therefore, cellulose I is produced by the function of CMCax
in orf2-disrupted strains. The facts that cellulose production in the
F2-2 culture was lower than that in the orf2-disrupted culture
(Fig. 1E) (25) and that the F2-2 strain mainly produces cellulose II
(Fig. 2) suggest thatCMCaxand ORF2 polypeptides collaborate in
cellulose crystallization and that cellulose I crystallization is severely
interrupted without the function of CMCax.