Journal:

Article Title: Crystal structure of a fibrillarin homologue from Methanococcus jannaschii , a hyperthermophile, at 1.6 ? resolution

doi: 10.1093/emboj/19.3.317

Figure Lengend Snippet: Fig. 2. (A) A comparison of the topological representations of the C-terminal domain of Mj0697 and the consensus catalytic domain derived from other methyltransferases (Vidgren et al., 1994; Schluckebier et al., 1995; Djordjevic and Stock, 1997). Helices are shown as circles, β-strands as triangles. The AdoMet-binding pocket is indicated. The location of the analogous pocket is indicated by an empty circle in the Mj0697 scheme. An extra helix present in the Methanococcus homologue that does not occur in the consensus domain is shaded darker. (B) Superposition of the Cα traces of the C–terminal domain in Mj0697 (black line), and of the methyltransferase catalytic domain in catechol O-methyltransferase, COMT (grey line). The diagram was prepared using INSIGHTII (Molecular Systems Inc.). (C) Structural-based sequence alignment of Mj0697 and COMT.

Article Snippet: The diagram was prepared using INSIGHTII (Molecular Systems Inc.). ( C ) Structural-based sequence alignment of Mj0697 and COMT.

Techniques: Comparison, Derivative Assay, Binding Assay, Sequencing

Journal:

Article Title: The structure of spider toxin huwentoxin-II with unique disulfide linkage: Evidence for structural evolution

doi:

Figure Lengend Snippet: Comparison between HWTX-II (A) and the inhibitor cystine knot motif molecules (B–E) with different disulfide bond numbers and linkage patterns. The backbone folding (in green), the sheet structures (in yellow) classified by Kabsch-Sander method in InsightII, and disulfide bonds are shown. (A) HWTX-II. Three disulfide bonds link in I-III, II-V, and IV-VI (C4-C18, C8-C29, and C23-C34) mode. (B) Huwentoxin-I. Three disulfides shown in yellow are linked in the typical ICK motif mode as I-IV, II-V, and III-VI (C2-C17, C9-C22, and C16-C29) (cf. Fig. 1 ▶). The III-VI disulfide passes through a ring formed by the I-IV and II-V disulfide bonds and the intervening peptide backbone, it is known as the cystine knot. (C) δ-atracotoxin-Hv1b. Four disulfides linked in C1-C15, C8-C20, C14-C31, and C16-C42 (cf. Fig. 1 ▶). (D) ω-agatoxin IVA. Four disulfides linked in C4-C20, C12-C25, C19-C36, and C27-C34 (cf. Fig. 1 ▶). (E) J-atracotoxin Hv1c. Four disulfides linked in C3-C17, C10-C22, C13-C14, and C16-C33 (cf. Fig. 1 ▶). The disulfide bonds involving in the cystine knot (I-IV, II-V, and III-VI) in the ICK motif structures, i.e. B, C, D, and E, are shown in yellow. The fourth additional disulfides (shown in red in B–E) in the ICK folding molecules are various and not involved in the cystine knot such as C16-C42 in δ-atracotoxin-Hv1b (C), C27-C34 in ω-agatoxin IVA (D), and C13-C14 in J-atracotoxin Hv1c (E). The ICK motif spider toxins with different disulfide bond numbers and linkages (B–E) all form the cystine knot, whereas HWTX-II (A) does not because of its unique disulfide bridges linkage. Moreover, the II-V and the IV-VI disulfide bond of HWTX-II (shown in yellow in A) dictating the C-terminal β-hairpin are similar to corresponding ones in ICK folding molecules (B–E). The disulfide I-III of HWTX-II (shown in red in A) is different from the corresponding ones of ICK folding molecules.

Article Snippet: The software InsightII (Biosym Technologies) was used to view and plot the structures.

Techniques: Comparison