Disulfide conformation and design at helix N-termini.

ABSTRACT: To understand structural and thermodynamic features of disulfides within an alpha-helix, a non-redundant dataset comprising of 5025 polypeptide chains containing 2311 disulfides was examined. Thirty-five examples were found of intrahelical disulfides involving a CXXC motif between the N-Cap and third helical positions. GLY and PRO were the most common amino acids at positions 1 and 2, respectively. The N-Cap residue for disulfide bonded CXXC motifs had average (phi,psi) values of (-112 +/- 25.2 degrees , 106 +/- 25.4 degrees ). To further explore conformational requirements for intrahelical disulfides, CYS pairs were introduced at positions N-Cap-3; 1,4; 7,10 in two helices of an Escherichia coli thioredoxin mutant lacking its active site disulfide (nSS Trx). In both helices, disulfides fo

SUBMITTER: Indu S 

PROVIDER: S-EPMC7167797 | biostudies-literature | 2010 Apr

REPOSITORIES: biostudies-literature