Lectin Domain Conserved Carbohydrate-binding Site Analysis

Analysis of conserved carbohydrate-binding residues in plant lectin domains using multiple sequence alignment and WebLogo conservation visualization.
Author

Beaven Manjengwa

Published

May 1, 2026

Keywords

carbohydrate binding, lectin domains, WebLogo, sequence conservation, ClustalOmega, MAFFT, plant lectins

Carbohydrate-binding Site Analysis

Objective of this section

Determine which identified lectin domains retain functional carbohydrate-binding activity by analyzing conservation of critical binding residues compared to model sequences and well-studied lectins from the literature.

Methodology overview

  1. Lectin domain sequences are extracted from Pfam (or relevant annotation) domain coordinates
  2. Untrimmed sequence alignments of lectin families with model sequences
  3. WebLogo3 generation for conservation visualization
  4. Visual inspection of conservation patterns at critical positions against the model sequence and known residues important for carbohydrate binding activity inferred from literature

Tools and databases

Tool Tested Version Platform (OS) Purpose
ClustalOmega1 1.2.4 Windows/Linux/Web Multiple sequence alignment (MSA)
MAFFT2 7.526 Windows, Linux, macOS and Web MSA
WebLogo33 3.7.12 Web tool and CLI (Linux) Conservation visualization

Table 1. Essential software tools and databases for that can be used in this analysis. {#tbl-tools}

Key insights

  • Conservation plots showing amino acid frequency at each position with conserved residues important for carbohydrate binding activity highlighted. Each column represents a stack of letters where letter height indicates frequency and overall stack height shows sequence conservation.
  • High conservation (>80%) at functional residues indicates likely activity. Missing critical residues suggests loss of activity and sequence divergence.
Figure 1: WebLogo of amino acids responsible for carbohydrate binding of the JRL (A), LysM (B), and Nictaba (C) domains. The conserved amino acids important for carbohydrate binding activity are highlighted in yellow. Adapted from Eggermont et al. (2017)4.

Key Limitations

  • Alignments often show extensive gaps which makes data interpretation difficult
  • Residues surrounding the binding pocket and overall protein structure can also influence specificity and activity
  • Different binding sites within the same protein can show different conservation levels making functional predictions inconsistent

Key Insights

  • Low sequence conservation across domains questions their functionality
  • Multiple amino acid residues in binding sites can be conserved but the domain may still be non-functional
  • Chimeric lectins may lose their carbohydrate-binding activity entirely

Published Studies

Phaseolus Species5, Arabidopsis thaliana4, and cucumber (Cucumis sativus)6

References

1.
Sievers, F. & Higgins, D. G. Clustal omega. Current Protocols in Bioinformatics 48, (2014).
2.
Katoh, K., Rozewicki, J. & Yamada, K. D. MAFFT online service: Multiple sequence alignment, interactive sequence choice and visualization. Briefings in Bioinformatics 20, 1160–1166 (2017).
3.
Schneider, T. D. & Stephens, R. M. Sequence logos: A new way to display consensus sequences. Nucleic Acids Research 18, 6097–6100 (1990).
4.
Eggermont, L., Verstraeten, B. & Van Damme, E. J. M. Genome-wide screening for lectin motifs in arabidopsis thaliana. The Plant Genome 10, plantgenome2017.02.0010 (2017).
5.
Osman, M. E. M. et al. Lectin gene families in three phaseolus species: Genome-wide identification, evolutionary analysis, pleiotropic effect, and regulation under multiple stress conditions. Journal of Molecular Evolution 94, 28–51 (2025).
6.
Dang, L. & Van Damme, E. J. M. Genome-wide identification and domain organization of lectin domains in cucumber. Plant Physiology and Biochemistry 108, 165–176 (2016).