A template for generation and comparison of three-dimensional selectin models

Area of Science:

• Biochemistry
• Structural Biology
• Immunology

Background:

• Selectins are cell adhesion molecules crucial for immune responses.
• Understanding the structure of selectin lectin domains is key to their function.
• Previous studies focused on sequence conservation, potentially missing broader structural insights.

Purpose of the Study:

• To identify structurally invariant regions in selectin lectin domains.
• To assess the feasibility of generating reliable three-dimensional models of selectins.
• To investigate the structural basis for differences in selectin specificity.

Main Methods:

• Comparative analysis of multiple sequence alignments of selectin lectin domains.
• Examination of structurally invariant regions using X-ray crystallographic data of mannose-binding protein (MBP) and E-selectin.
• Development of a three-dimensional model for the L-selectin lectin domain.

Main Results:

• Structural conservation between MBP and E-selectin extends beyond sequence-conserved regions.
• Identified key backbone segments in E-selectin amenable to modification for modeling.
• Generated a model of the L-selectin lectin domain highlighting structural determinants of specificity.

Conclusions:

• Structural modeling of selectins can be achieved by modifying limited backbone segments.
• Conserved structural features, not just sequence, are critical for selectin function.
• The developed models provide insights into the molecular mechanisms underlying selectin specificity.