ERCC6L2/Hebo ATPase domain. (A) Sequence alignment of the human ERCC6L2 SWI/SNF2 ATPase domain with those of the Rad54 proteins of known 3D structures (D. rerio, Protein Data Bank accession no. 1z3i [Thomä et al., 2005]; and Sulfolobus solfataricus, Protein Data Bank accession no. 1z63 [Dürr et al., 2005]). SWI2/SNF2-specific elements are depicted in magenta (HD1) and green (HD2), whereas the RecA-like helicase domains are blue (lobe1) and red (lobe2). Helicase-specific domains are shown with numbers, and SWI-SNF2–specific elements are depicted with letters (Thomä et al., 2005). Yellow boxes (alignment) indicate the positions of insertions in the ERCC6L2 structure relative to the Rad54 templates. (B) Global view of the 3D structure model (ribbon representation) of the human ERCC6L2 SWI/SNF2 ATPase domain, constructed on the basis of its alignment with sequences of known 3D structures (see A). The same colors are used as in A. Circles (3D structure) indicate the positions of insertions in the ERCC6L2 structure relative to the Rad54 templates (yellow boxes in A). (C) Focus on the HD2 domain showing the location of arginine 655. N-ter, N-terminal. C-ter, C-terminal.