H-BloX

H-BloX computes and visualizes Shannon information content and relative entropy (Kullback-Leibler 'distance') across sequence alignment blocks to quantify conservation and chemical diversity.

Key Features:

• Versatile Input Compatibility: Accepts amino acid sequences, nucleic acids, or any aligned chemical structures for analysis.
• Entropy Calculations: Computes Shannon information content and relative entropy (Kullback-Leibler 'distance') within sequence alignment blocks.
• Custom Alphabet Conversion: Requires conversion of numerical data into a user-defined character alphabet prior to entropy or information-content computation.
• Hydrophobicity-based Alphabet: Converts amino acid sequences into an alphabet based on hydrophobicity assignments to analyze hydrophobic features.
• Visualization of Information Content: Produces visual representations of information content or relative entropy mapped onto alignment blocks.

Scientific Applications:

• Signal peptide analysis in Escherichia coli: Revealed the hydrophobic core region and the characteristic '-3,-1' cleavage site pattern, pinpointing the hydrophobic-core center at amino acid residue position 13 from the N-terminal end of the precursor sequence.

Methodology:

Computes Shannon information content and Kullback-Leibler relative entropy within sequence alignment blocks; converts numerical data into user-defined character alphabets and converts amino acid sequences into hydrophobicity-based alphabets prior to entropy computation.