Question

Which of the following is a multiple sequence alignment tool?

• A. SCOP
• B. PDB
• C. GOLD
• D. Clustal W

Hint:

Clustal W uses a progressive alignment approach where the 'W' stands for 'weighting', indicating its ability to weight individual sequences and vary gap penalties dynamically to improve alignment accuracy.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Multiple Sequence Alignment (MSA) is a fundamental bioinformatic process used to align three or more biological sequences (DNA, RNA, or protein) of similar length.
This alignment identifies regions of evolutionary conservation, homologous relationships, and structurally or functionally important residues.

Step 2: Detailed Explanation:
Let us evaluate each of the bioinformatic tools and databases mentioned in the options:
1. Clustal W is a widely utilized, classic computer program designed for multiple sequence alignment.
It employs a progressive alignment algorithm that first calculates pairwise distance matrices between all sequences.
Following this, it constructs a guide tree (phylogenetic tree) and aligns the sequences progressively according to the branching order of the tree.
2. SCOP (Structural Classification of Proteins) is a database that manually classifies protein 3D structures based on evolutionary and structural relationships.
3. PDB (Protein Data Bank) is a global repository for 3D structural data of large biological molecules, such as proteins and nucleic acids, determined by X-ray crystallography, NMR spectroscopy, and cryo-EM.
4. GOLD (Genomes OnLine Database) is a comprehensive resource for metadata regarding genome and metagenome sequencing projects worldwide.
Therefore, Clustal W is the correct multiple sequence alignment tool.

Step 3: Final Answer:
Clustal W is a multiple sequence alignment tool, which corresponds to option (D).