Structural comparisons of
representative treble clef fingers. (A) Structural
diagrams of ribosomal protein S14 (1fjf, chain N, residues 21–53),
ribosomal protein L24E (1ffk, chain R, residues 3–45),
RING finger of RAG1 (dimerization domain) (1rmd, residues 23–60),
ARF-GAP domain of Pyk2-associated protein β (1dcq,
chain A, residues 262–297), Cys2 activator-binding domain
of protein kinase Cδ (1ptq,
residues 241–280), FYVE domain of Vps27p protein, first
treble clef finger (1vfy, chain A, residues 172–207), FYVE
domain of Vps27p protein, second treble clef finger (1vfy, chain
A, residues 190–235), retinoid X receptor α DNA-binding
domain (2nll, chain B, residues 300–336), recombination
endonuclease VII (1en7, chain A, residues 19–79), MH1 domain
of Smad (1mhd, chain A, residues 93–132) showing the treble
clef finger domains from each protein. In each protein, N- and C-termini
are labeled with N and C. β-Strands
and α-helices are labeled in lower and
upper case letters, respectively. The color of the letter corresponds
to the color of the element. The short β-strands
in the zinc knuckle region are shown in purple (a and b) with the zinc knuckle turn colored red. Side-chains
of zinc ligands and corresponding residues in 1mhd are shown in
ball-and-stick representation. Zinc ions are shown as orange balls.
The ribbon diagrams were rendered by Bobscript (23), a modified
version of Molscript (24). (B) Stereo diagram of
superimposed Cα-traces of
the 10 structures from (A) shown in the same orientation. The Cα-traces of proteins, side chains
of zinc ligands and Zn2+ are shown. Superpositions
were made using Insight II package (MSI). The regions used in r.m.s.d.
minimization are outlined in thicker lines. Color coding of structures corresponds
to the dot color scheme (in front of each PDB entry) in (C). (C) Structure-based sequence alignment of treble
clef motif regions of the 10 proteins illustrated in panel (A).
For each sequence, the PDB entry name and chain ID, starting and
ending residue numbers are given. Zinc ligands are boxed in black.
Color shading and labels of secondary structure elements correspond
to those in (A). Long insertions are not displayed: the number of
omitted residues is specified in brackets.