 |
|
Title
|
|
Cloning and characterization of a xylanase gene from corn strains of Erwinia chrysanthemi.
|
|
|
Authors
|
|
N.T.Keen,
C.Boyd,
B.Henrissat.
|
|
|
Ref.
|
|
Mol Plant Microbe Interact, 1996,
9,
651-657.
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
The gene encoding a 42-kDa endoxylanase was cloned from Erwinia chrysanthemi
strain D1. Sequencing of this gene, called xynA, showed that it encoded a
primary protein product of 413 amino acids with an unusual and long (31 amino
acid) leader peptide that was cleaved during secretion to the bacterial
periplasm. This protein is distinct from xylanases in glycohydrolase families 10
and 11 and, instead, appears to be intermediate between families 5 and 30. The
xynA gene is located downstream from a gene with high homology to ATP-dependent
RNA helicases and the Escherichia coli recD gene. Large amounts of the mature
xylanase were produced by E. coli cells carrying a T7 expression plasmid
construct and the protein was isolated from the bacterial periplasmic fraction
by chromatography on a CM Bio-gel column. Marker exchange mutagenesis of the
xynA gene eliminated the ability of strain D1 to produce detectable
extracellular xylanase activity but did not affect virulence on corn leaves.
|
|
|
|