It is, therefore, conceivable that this downstream binding may reflect an additional function of the Tip60 complex that may play a role in the early steps of transcription elongation processes, as suggested also in Drosophila [ 45].
Most de novo GATA2 peaks display weak binding of GATA1 (not shown); thus, de novo GATA2E binding may reflect an intermediate stage of the erythroid program, where sites that are not primed by GATA2 in MPCs sequentially bind GATA2 and then GATA1 as their expression increases during differentiation.
The discrepancy between RBf protein binding and E2F factor binding may reflect the two different developmental stages used for measuring binding, although many individual genes are similarly bound in both stages (Acharya et al. 2012; Korenjak et al. 2012).
It can be conjectured that the presence of genes, which have lost (or not still acquired) the binding sites, may reflect a relatively recent evolutionary divergence, such as is expected among strains of the same species and confirmed in the case of nolR, whose inactivation in the laboratory strain Rm1021 probably happened recently, since even its DNA-binding sites are conserved.
The favourable entropic component of binding of the lead series may reflect a disordered binding mode and may explain the difficulties in obtaining a crystal structure in complex with the protein.
We suggest that the long delay between HIV binding and membrane fusion may reflect a sequence of events similar to those in our model for influenza virus fusion.
Interestingly, Prep1 contains a putative binding motif for 4EHP, which may reflect a novel unknown function.
The kinetic and binding results with the lysine mutant may reflect a steric clash with the cofactor, despite our observation in crystals that it could be oriented toward the metal center.
Sp17's binding to A-kinase anchoring protein 3 (AKAP3) may reflect a functional need for Ca2+/CaM at sites along the flagella, where Ca2+/CaM is known to play a role in motility.
Alternatively, it may reflect a strong influence of chromatin accessibility on the binding profile coupled with low-specificity widespread binding of both homeodomain proteins.
