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homology with other plant chitinases. In Bar2chi gene the cysteine-rich chitin
binding domain (CBD) was identified as prototypical feature of class
1
chitinase as
reported earlier (Iseli
el
al.. 1993; Ignatius
el
rrl.,
1994). Yun
6.1
ol.. (1996) concluded
that native class I chitinases that contain CBDs have greater ;mtifungnl activities than
isoforms that do not have this domain. The Bor2chi gene dots contain a TATA box
between positions 503 and
509
and a polyadenylntion signal hetween positions 1651
and 1657 (Ignatius
er
al.. 1994).
Results indicated that the Ltp 3F1 gene isolated from then cDNA librnry of
wheat belonged to the member of PR-14 family. Amino acid alignment studies of Ltp
3F1 (348 bp) revealed typical features of plant LTPs, viz.. absence of tryptophan and
phenylalanine. and conservation of eight cysteine residues that could form a network
of disulfide bridges necessary for the maintenance of the tertiary structure of the
molecule together with the central helical core, while the variable loops would
provide the sequences required for the specific functions of the proteins (Jose-
Estanyol
et
al., 2 W ) . Phylogenetic analysis indicated the high level homology of
Llp
3F1 with other monocot LTPs.
Molecular modeling studies revealed that the structure of barley chitinase
Bar2Chi (P11955) and wheat
LTP
3F1 (EF432573) showed similarity with
another barley chitinase
(PDB
code 1CNS) and maize ns-LTP (PDB code I A M )
respectively. The secondary structure of chitinase reported in this study revealed the
presence of 13 a-helices, 5 P-strands and 28 loop turns and the presence of 6
conserved cysteine residues that are responsible for the formation of 3 disulphide
bridges (Cys98-Cys160. Cys172-Cys180 and Cys279-Cys311). The active site
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