Pectin methylesterase, 1GQ8; a typical β-helix. 1GQ8 is a right-handed β-helix, three-sided, with a single α-helix cap at its N terminus and a previous-strand visor cap at its C terminus. Inset, the assignment of β-strand and turn names in a β-helix rung as seen in residues 167-225 of pectate lyase C (2PEC), a similar β-helix.