141. Saxena, I. M. , Lin, F. C. and R. M.
Brown, Jr. l99l. Identification of a new gene in an operon for
cellulose biosynthesis in Acetobacter xylinum. Plant
Molecular Biology 169:947-954.
DNA sequencing of the region downstream
of the cellulose synthase catalytic subunit gene of Acetobacter
xylinum led to the identification of an open reading frame
coding for a polypeptide of 86 kDa. The deduced amino acid sequence
of this polypeptide matches from position 27 to 40 with the N-terminal
amino acid sequence determined for a 93 kDa polypeptide that copurifies
with the cellulose synthase catalytic subunit during purification
of cellulose synthase. The cellulose synthase catalytic subunit
gene and the gene encoding the 93 kDa polypeptide, along with
other genes probably, are organized as an operon for cellulose
biosynthesis in which the first gene is the catalytic subunit
gene and the second gene codes for the 93 kDa polypeptide. The
function of the 93 kDa polypeptide is not clear at present, however
it appears to be tightly associated with the cellulose synthase
catalytic subunit. Sequence analysis of the polypeptide shows
that it is a membrane protein with a signal sequence at the N-terminal
end and a transmembrane helix in the C-terminal region for anchoring
it into the membrane.