Considerable weak discernible residues associated with the use of bio-colorants are: reproducibility, cost efficiency, inadequate degree of fixation, and low color fastness properties [59, 93, 94].
For example, it is well-known that the N-terminal non-globular region of Thermus thermophilus seryl-tRNA synthetase (PDB 1SRY) [ 1, 8] has weak 7-residue repeats.
Based on the patterns, which were only partially conserved, it became apparent that this element was probably a quite diverged RR. (i) The sequence contained only weak hydrophobic residues in the region corresponding to beta-strand-1.
The insert in F1 is located between strands β3 and β4 as part of a large 35-residue loop (residues 133 170) that is unstructured and highly dynamic, as shown by intense sharp signals in the [H,N]-HSQC spectra, and the presence of only weak intra-residue and sequential NOE interactions within the loop.
However, since arginine and threonine are both strong polar residues, whereas methionine and tryptophan possess bulky hydrophobic side chains, and cysteine is a weak-polar residue prone to various post-translational modifications, the R649W, T651M, and R655C mutations bear the possibility to interrupt the association between the protein and other protein partners or incur unexpected modifications.
We find that although the MEL5 TCR bound with an identical overall conformation to A2-EAA and A2-ELA, the weaker anchor residue at position 2 in the natural peptide enabled the TCR to "pull" the peptide away from the MHC peptide-binding groove.
Disruption of individual weak-functioning residues can frequently be tolerated, confounding current mutation-counting sequencing efforts.
However, equivalent interactions are not observed in the three GPCR crystallized in their active conformation, whereas four of the 18 GPCR inactive experimental structures used in this study (16 structures used as templates plus 2 structures not used as templates due to low amino acid sequence identity) show weak contacts between residues at positions 3.30 and 4.58.
These small shifts may occur due to loss of the Y1065 phenol, since this side chain forms weak contacts with residues in the Vt N-terminus.
The 10 most-frequent hexamers in standardized promoters of Arabidopsis were similar to those in standardized promoters of rice and soybean, with only W (Weak 2H bonds) residues (Supplementary Tables S13 S15).
