# 4.3 Sequence Alignments and BLAST

> Sequence Alignments and BLAST (Module 4: The Bioinformatician's Toolkit). Key concept: Sequence similarity searches. Explain what a sequence alignment reveals that a single sequence cannot.

Sequence Alignments and BLAST (Module 4: The Bioinformatician's Toolkit). Key concept: Sequence similarity searches. Explain what a sequence alignment reveals that a single sequence cannot.

- Explain what a sequence alignment reveals that a single sequence cannot
- Interpret BLAST output: E-value, percent identity and query coverage
- Read a multiple sequence alignment for conserved and variable positions
- Explain the core insight: conservation marks constraint, and variability marks design freedom
- Predict whether a conserved position is constrained by structure or by function

## Links

- [Module 4: The Bioinformatician's Toolkit](https://proteindesign.academy/module/4)
- [4.1 Reading a PDB File](https://proteindesign.academy/module/4/1)
- [4.2 Navigating a 3D Molecular Viewer](https://proteindesign.academy/module/4/2)
- [4.4 Evolutionary Conservation and ConSurf](https://proteindesign.academy/module/4/4)
- [4.5 Structure Prediction Landscape](https://proteindesign.academy/module/4/5)
- [The Structural Biologist](https://proteindesign.academy/module/4/capstone)