Sandbox chameleon

Chamelion

General question

To determine the extent to which non-local factors influence the formation of secondary structural elements

Methodology

Design the longest possible sequence that can fold into an alpha-helix when inserted into one place in a protein sequence and a beta-sheet when inserted into another. Two key references to read on this ones on a Chameleon peptide^[1] and an analysis of Helix-to-Strand Transition Between Peptides with Identical Sequences^[2].

Seeing is believing

The IgG-Binding domain is displayed in Rainbow colors, i.e. going from Blue--->Red from N--->C terminal. To simplify things, the entire chain is colored .

Now displaying the mutated structure, where 5 amino acids, in the region , are change to the Chameleon sequence, i.e. AWTVEKAFKTF

TTYKLILNGKTLKGETTTEAVDAATAEKVFKQYANDNGVDGEWTYDDATKTFTVTEK

TTYKLILNGKTLKGETTTEAVDAWTVEKAFKTFANDNGVDGEWTYDDATKTFTVTEK

If a similar change from the Wild-Type to where 5 amino acids, in the region are changed to the Chameleon sequence, specifically from/to:
TTYKLILNGKTLKGETTTEAVDAATAEKVFKQYANDNGVDGEWTYDDATKTFTVTEK
TTYKLILNGKTLKGETTTEAVDAATAEKVFKQYANDNGVDGAWTVEKAFKTFTVTEK

The Chameleon sequence, AWTVEKAFKTF, appears to adopt to its environment.