A tale of two symmetrical tails: Structural and functional characteristics of palindromes in proteins

Background: It has been previously shown that palindromic sequences are frequently observed in proteins. However, our knowledge about their evolutionary origin and their possible importance is incomplete. Results: In this work, we tried to revisit this relatively neglected phenomenon. Several questions are addressed in this work. (1) It is known that there is a large chance of finding a palindrome in low complexity sequences (i.e. sequences with extreme amino acid usage bias). What is the role of sequence complexity in the evolution of palindromic sequences in proteins? (2) Do palindromes coincide with conserved protein sequences? If yes, what are the functions of these conserved segments? (3) In case of conserved palindromes, is it always the case that the whole conserved pattern is also symmetrical? (4) Do palindromic protein sequences form regular secondary structures? (5) Does sequence similarity of the two "sides" of a palindrome imply structural similarity? For the fir...

• Type: Journal
• Year: 2008
• Where: BMCBI
• Authors: Armita Sheari, Mehdi Kargar, Ali Katanforoush, Shahriar Arab, Mehdi Sadeghi, Hamid Pezeshk, Changiz Eslahchi, Sayed-Amir Marashi
• Keywords: BMCBI 2008, Palindrome, Protein, Sequences