Question

Question: Identify a 20-residue segment that could form a transmembrane α helix in this protein sequence (from the mosquito Orco).

Short answer

Answer

20 residue segment that forms the $\alpha$transmembrane helix in the protein sequence

Step-by-step solution

Transmembrane domain

The transmembrane domain in a transmembrane protein represents the transmembrane portion of a single alpha helix. Alpha-helical proteins are found mostly in the inner membranes of bacteria and the plasma membranes of eukaryotes. It's the most common type of transmembrane protein.

Residue to form transmembrane protein

The water components are eliminated when two or more amino acids unite to create a peptide, and the residue of each amino acid is referred to as an amino-acid residue. An amino acid is coded for in each protein sequence. The amino acid must be hydrophobic to be a transmembrane protein. The underlined protein sequence represents a transmembrane alpha helix-forming sequence. Hydrophobic amino acids are those that code for this sequence.

Pictorial representation of residue

Therefore, the 20 residue segment forms the transmembrane helix in the protein sequence.