The authors established a knock-in mouse where the critical CD3ε motif was replaced by another sequence naturally occupying an analogous sequence in the cytoplasmic tail of FcεR1γ to assure an unaltered distance of the CD3ε ITAM from the membrane and the neighbouring CD3 subunits.
Replacement by a new sequence may occur not as a satellite sequence covering the entire centromere region, but as a sequence occupying a specific region of the centromere.
This result highlights a dynamic process in which a transient preference of a nucleosome for occupying a thermodynamically favorable sequence is converted over time to an alternative chromatin conformation.
To describe a residue of the leader sequence, occupying a work position, we used the secondary structure state (H or E), the generalized topohydrophobic parameter y1 deduced from the multiple sequence alignment, the group parameter G 1 (0 or 1) of the considered residue and four environment parameters EnvIn reply to: (i= 1, 4) associated with positions i. EnvIn reply to: = (Gn−i + Gn+i)/2.
In particular, the branching pattern of archaeal sequences, occupying a key place in the history of recA recombinases, differs between these studies (compare Additional file 1 Figure S1A and S1B).
Sequences occupying an ambiguous position in the genome were removed.
Since loops are more flexible, the K might easily perform the same function as an R without occupying an identical position in the sequence.
For example, mutagenesis experiments suggest that the amino acid sequences forming an enzyme with the same structure and function as chorismate mutase may occupy a fraction 10−23 of sequence space [13], whereas sequences forming a functional β-lactamase domain occupy merely one 10−64th of sequence space [14].
The absence of physical dividers between the sites occupied by individual oligonucleotides, a very limited space on the surface of the microarray (one oligonucleotide sequence occupies a square 25×25 μm) and the requirement of high fidelity of oligonucleotide synthesis dictate the use of site-selective 5'-deprotection techniques.
If a fosmid carries repetitive DNA (such as AS) as its insert, the same sequence occupies a large fraction of the probe DNA.
