Domain sketch of NSF protein and the amino acid conservation of the N-D1 linker.

<p>The diagram shows the structural domains of NSF: the N-terminal domain, D1 and D2 AAA+ modules. The position of the N-D1 linker and D1-D2 linker are indicated. Sequence alignment of the N-D1 linker from different eukaryotic species shows that the N-D1 linker is highly conserved. The numbers at the two ends of the sequence indicate the amino acid residues in NSF. Residues are colored by similarity. The letters under the sequence indicate the amino acid substitutions constructed in this study.