Although previous studies demonstrated that a specific amino acid sequence is required for nucleolar localization, the RNA-binding domain has not been identified.
Although the accumulation of L22 in nucleoli has been demonstrated and a specific amino acid sequence has been shown to contribute to nucleolar localization [29], an RNA-binding domain has not been defined, nor has a link between rRNA binding and nucleolar accumulation been established.
The Gemin2 residues involved in binding to SMN are located throughout the sequence, explaining why more extensive deletions into the 95 280 construct result in loss of SMN-binding activity [ 29] and why a smaller SMN-binding domain has not been previously reported.
In contrast, the putative transcription factor, which contains a predicted basic helix−loop−helix DNA-binding domain, has not previously been implicated in the regulatory control of tocochromanol biosynthesis, though this is possible as it is expressed at low levels in developing embryos (Sekhon et al. 2011).
Further, binding of Peak 3 to gelatin and its recognition by L8 and 5C3, which occur only under non-reduced conditions [26], [45] (and results not shown), indicated that at least part of the gelatin-binding domain had not been completely reduced, alkylated, and digested during preparation of the fragments.
To our knowledge, however, the relationship of the α1 domain to other DNA-binding domains has not been documented.
Previous in vitro cleavage assays on partially randomized substrates revealed that wild-type I-TevI can accommodate nucleotide substitutions in the DNA spacer (Bryk et al. 1993), yet whether the I-TevI linker can tolerate nucleotide substitutions in the context of engineered DNA-binding domains had not yet been determined.
Yet the DNA binding activity of either domain has not been directly demonstrated.
The long fiber of HAdV-F members can bind CAR; a cellular receptor capable of binding the short fiber knob domain has not been identified.
DNA binding impairment of this protein domain has not been characterized biochemically and was not detected in our cellular assay with full-length protein.
