Figure 1
(a) Schematic view of the various domains of ERG3 proteins. The ETSi construct used in the current study contains residues 307–392 of the ETS domain and residues 393–399 of the adjacent CID domain of ERG3 (shown in yellow). (b) Sequence alignment of the ETSi domain of ERG3 with sequences from 11 other ETS class 1 protein–DNA complexes of known structure: Fli1 (PDB entry 5e8i), Fev (PDB entry 3zp5), Etv5 (PDB entry 4uno), Etv1 (PDB entry 4bnc), Etv4 (PDB entry 4uuv), Ets1 (PDB entry 3mfk), GABPα (PDB entry 1awc), Ets2 (PDB entry 4bqa), Sap1 (PDB entry 1bc7), Elk1 (PDB entry 1dux) and Etv6 (PDB entry 4mhg). The MultiAlin (Corpet, 1988) and ESPript 3.0 programs (Robert & Gouet, 2014) were used for multiple sequence alignment and structure prediction. The secondary structures of the ETSi domain are shown above the sequence alignment, with α-helices as spirals and β-strands as arrows. Highly conserved residues are shaded red and less conserved residues are shown as red and blue letters. The lower panel shows the DNA9 sequence used in the current study. (c) The DNA sequence of the ETSi–DNA9 complex is aligned with the DNA sequences of 11 ETS class 1 protein–DNA complexes. Except for the DNA sequences from the ETS1–DNA and ETV6–DNA complexes, the nine base pairs of other ETS class 1 protein–DNA complexes are similar to the DNA9 sequence. (d) Size-exclusion chromatography and SDS–PAGE analysis of the purified ETSi domain. The ETSi domain eluted as a dimer from the size-exclusion column and shows a single band on SDS–PAGE. |