The aptamer in its ligand-binding competent structure represents one structural conformation of the switch while an alternative fold that disrupts the binding-competent structure forms the other conformation.
More energy is required for ergosterol synthesis than for cholesterol, and in addition cholesterol has been shown to be the most functionally competent structure in artificial membrane systems [31].
Since IZUMO1 has a simple structure compared to other fusion proteins [6] with no "fusogenic" peptide or "SNARE" like structure in it, we entertained the possibility that IZUMO1 is one of the components that form a fusion competent structure on sperm.
In the subclass IB RcFPR:NADP+ complex, the nicotinamide hydride donor protrudes towards the solvent, far from producing a competent structure for hydride transfer [ 13].
Ccm1p would perfectly fit this scenario as a factor that assists the full-length bI4 intron in acquiring the competent structure towards a catalytic form.
Debridement of necrotic soft tissues with the aim of preserving the synovial membrane as an immune competent structure and natural barrier, is recommended by the majority of the authors [ 4- 6, 10, 25, 28, 29, 33, 35, 37, 44, 47- 49].
Furthermore, distinct spatial interactions of the LCR in fetal and adult stages were uncovered by another study based only in 3C assay in which HBD sequence was proposed to be enrolled in the maintenance of a transcriptionally competent structure at the adult stage (Beauchemin and Trudel 2009).
This cleavage event results in structural rearrangements in which the nonpolar N-terminus amino acids of HA2 (the fusion peptide) are repositioned to the interior of the trimer, thereby burying the ionizable residues in the cleaved HA and generating a fusion competent structure [ 45].
We propose that this occurs initially to establish the catalytically competent structure of the replication fork T7 DNAP melts two base pairs and binds two ssDNA nucleotides in its template-binding pocket, which positions the helicase two nucleotides ahead at the fork junction, as shown in Figure 6.
In the absence of yKu, TPE is disrupted and less Sir3 and Sir4 are present in the subtelomeric regions [ 25- 27], indicating that yKu is required in order to facilitate either the recruitment of the Sir complex or the assembly of a silencing competent structure.
