By means of the first generated pattern no novel sequences were r

By means of the first generated pattern no novel sequences were retrieved by regular expression search. This first attempt failed due to the high pattern specificity, since it was constructed based on only eight sequences. Therefore, a more generalized pattern was needed, in order to find the

uncharacterized hevein-like peptides precursors in NR. Among the five originally identified precursors, three of them (CBI18789 from V. vinifera, EEE61250 from O. sativa and XP_002962191 from S. moellendorffii) have sequences larger than the hevein domain. This feature had already been observed for the Rapamycin hevein-like precursors of Ac-AMP2 [9], Ar-AMP [37] and WAMP-1 [3]. In fact, these sequences after the hevein domain are propeptides and are posteriorly cleaved, leaving the mature peptide. In the case of hevein-like peptides,

the propeptides could be related to the evolution process which originated this class. Andreev et al. [3] have proposed that the WAMP-1 peptide emerges from a deletion of the catalytic domain of a chimerolectin (class I chitinase from plants). These three peptides with sequences after the hevein domain also show similarities to chimerolectins (data not shown), indicating that these sequences may be originated from a similar evolutionary process of WAMP-1. There are two other hypotheses involving the evolution of lectins with the hevein domain, which propose duplication BMS-354825 chemical structure or transposition of hevein domains, contrasting with Andreev et al. [3]. Wright et al. [62] have proposed that the consecutive duplication of hevein domains in the same gene generated the hololectins, and Shinshi et al. [50] have suggested that the transposition of an hevein domain into the gene of a chitinase generated the chimerolectins. Presumably, these sequences

after the hevein domain are remnants of the evolutionary process. In CBI18789 (V. vinifera), this sequence corresponds to a short hydrophobic tail. This tail does not generate great changes in structure and, probably, neither in protein function. In fact a transition next of coil-to-β-sheet was observed in MD, however, without influences in the binding to (GlcNAc)3 (data not shown). In addition, there is no clear evidence that this tail is cleaved. Similarly, XP_002962191 from S. moellendorffii also shows an additional sequence after the hevein domain. Nonetheless, it is longer than CBI18789′s tail and, in this case, there may be a structural or functional change if it is not cleaved. Hence, it was removed from the analysis, since clear evidence of cleavage was not observed. In contrast, EEE61250 (O. sativa) has a similar cleavage site to Ac-AMP2 and Ar-AMP, indicating that the additional sequence may be a propeptide. In this last case, besides the cleavage site, these sequences also share the same number of cysteine residues. The other two retrieved sequences have only the signal peptide and the hevein domain, without additional sequences after the hevein domain.

Leave a Reply

Your email address will not be published. Required fields are marked *


You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>