Skip to main content
. 2011 Jun 17;108(27):11099–11104. doi: 10.1073/pnas.1017504108

Fig. 2.

Fig. 2.

α-helix and visor cap structures. All α-helix caps displayed are N-caps and all visor caps displayed are C-caps, except for (I), where both N- and C-caps are visors. For visibility, other domains and distant portions of the β-helices have been removed. All images were produced using PyMol (www.pymol.org). (A–C) Representative α-helix N-caps. Structural components used in HELIXCAP-HMM prediction are labeled: black labels, AE; red labels, α-helix; and green labels, first rung. (A) 1BN8 (residues 33–46 shown); (B) 1GQ8 (residues 8–32 shown); (C) 1KQA (residues 22–54 shown). (D–I) Representative visor family caps. (D) 1KQA (residues 53–190 shown), a previous-strand visor on a left-handed β-helix; (E) 1JTA (residues 260–340 shown), a previous-strand visor on a right-handed β-helix; (F) 1G95 (residues 376–441 shown), a cross-helix visor on a left-handed β-helix; (G) 1DBG (residues 379–433 shown), a cross-helix visor on a right-handed β-helix; (H) 2PEC (residues 217–316 shown), a cross-helix visor containing an α-helix on a right-handed β-helix; (I) 1HF2 (residues 90–206 shown), a structure with visor caps at both the N- and C-terminal ends. Detailed discussion of these cap types may be found in SI Text.