B.B. Patnaik2, H.J.
S. Baliarsingh2, J.M.
M.K. Sang1, H.R. Min1,
H.C. Cho1, S.W. Kang3,
S.Y. Park4, H.S. Park5,
and Y.S. Lee1* ??
1Department of Life
Sciences and Biotechnology, College of Natural Sciences, Soonchunhyang
University, 31538, Korea
2School of Biotech
Sciences, Trident Academy of Creative Technology, Bhubaneswar-751 024, India
Resource Center, Korea Research Institute of Bioscience and Biotechnology
(KRIBB), Jeongeup, 56212, Korea
4Animal & Plant
Research Department, Nakdonggang National Institute of Biological Resources,
Sangju, Gyeonbuk, 37242, Korea
Institute, GnC Bio Company Ltd.,? Daejeon, 34069, Korea
basic sciences, College of Natural Sciences, Soonchunhyang University, Asan,
Chungnam, 31538, Korea
Author Email :
Aim: Galectins are
β-galactoside binding proteins currently represented by 15 members
(Galectin-1 through Galectin-15). The members are differentiated on the basis
of the number of carbohydrate recognition domains (CRDs), the linker region
connecting dual CRDs, and the conserved amino acid (aa) residues within CRDs.
In this study, galactosyl-binding lectin family proteins were screened and
characterized from transcriptome of terrestrial slug Incilaria
fruhstorferi using bioinformatics analysis.
fruhstorferi unigene sequences showing identity to galectins in the
orthologous species were used for prediction of ORFs using FGENESH software.
Subsequently, the ORFs were validated for conserved domain analysis using
BLASTp and SMART programs. The multiple sequence alignments and percent
identity/distance was elucidated using Clustal X2 and represented in GeneDoc
sequence visualization program. The phylogenetic tree was inferred using
Results: A single-repeat
and a tandem-repeat galectin (If_Gal6 and If_Gal4, respectively) were
retrieved from the transcriptome profile of terrestrial slug, I.
fruhstorferi. The predicted If_Gal4 and If_Gal6 comprised of 693
nucleotides translated to 230 aa residues and 435 nucleotides translated to
144 aa residues, respectively. If_Gal4 possessed two CRDs, each showing the
highly conserved aa responsible for galactosyl-binding activity.
Surprisingly, If_Gal6 is a single-CRD protein in contrast to the common
tandem-repeat galectins illustrated for Gal6 in most other invertebrate and
vertebrate species. At the level of aa sequence, If_Gal4 showed maximum of 54%
identity and minimum distance of 0.459 with the sea snail, Haliotis discus
Galectin-4 (Hd_Gal4). Cluster analysis showed higher similarities of If_Gal4
with selected molluscan Galectin-4 aa sequences. If_Gal6 showed 41% identity
with the air-breathing freshwater snail, Biomphalaria glabrata Galectin-6
(Bg_Gal6) supposed to exist as dual-CRD molluscan galectin.
Interpretation: Discovery and
structural characterization of a single-CRD galectin from I. fruhstorferi
is second in molluscs after the sequence was reported from the Pacific
oyster, Crassostrea gigas.
Key words: Carbohydrate-recognition domains, Galectin, Incilaria
fruhstorferi, Phytogenetic analysis