The paper:
H. Tagami et al., "Histone H3.1 and H3.3 complexes mediate nucleosome assembly pathways dependent or independent of DNA synthesis," Cell, 116:51-61, 2004. (Cited in 146 papers)
The finding:
Yoshihiro Nakatani's group at Dana Farber Cancer Institute and Geneviève Almouzni's group at Curie Institute in France identified the chaperones responsible for depositing histone complexes H3.1 and H3.3 into chromatin through two distinct pathways. Steven Henikoff at Fred Hutchinson Cancer Research Center says, "It was very satisfying to see their results," because he had suspected that two pathways exist - replication-independent and replication-dependent - and Nakatani's biochemistry confirmed it.
The surprise:
During purification of the histone complexes the authors found evidence that the complexes possessed a pair of H3/H4 histone dimers, rather than the tetramer that had been hypothesized. Nakatani says a dimer model of the histone complex helps explain...