These results are consistent with the hypothesis that C333 and C367 constitute a biarsenical-binding site, with the Shp-specific C333 acting as the key specificity determinant.
Phe261 is a key specificity determinant in the α-helical cap of the Ω-loop when folded into the closed conformation.
These structures show that an invariant glutamine functions as the key specificity determinant by a "glutamine switch" mechanism for recognizing the purine moiety in cAMP or cGMP.
As a proof-of-concept of this idea, Skerker et al. [ 19] showed that the specificity of an HK to its RR in TCS can be rewired by rational mutation of key specificity amino acids within and/or transplanting DHP subdomains within the HK domain.
DYW-type PPR proteins are postulated as the key specificity determinants in C-to-U type editing (Salone et al. 2007; Zehrmann et al. 2009; Hayes et al. 2013), and co-occurrence of the DYW domain and organelle RNA editing is well documented in land plants (Rüdinger et al. 2012).
We first provide additional evidence supporting the formation of an acyl-enzyme intermediate during the hydrolysis of fluoroacetyl-CoA, and we show that the rate of formation of this intermediate does not depend on the key specificity-determining residue, His 76, which is involved in Cα deprotonation.
Our recent positional scanning peptide library analysis has revealed key substrate-specificity requirements of PCTAIRE-1 [ 6].
They are likely to hold the key to specificity in terms of targeting these proteases to protein complexes and cellular compartments, serve regulatory functions, and play a role in substrate selectivity such as in the most well studied member of the USP family USP7/HAUSP.
The implanted tissue maintained both tissue and species-specificity, even expressing key organ-specific biomarkers.
This donor tissue can do so on its own as shown in our 2007 Nature Biotechnology article in which we state that the donor implanted tissue's blood vessels "maintained both tissue- and species-specificity, even expressing key organ-specific biomarkers".
Our goals were to (1) identify sequences which could uniquely identify cardiac or renal injury (crucial to a sensitive diagnostic) and (2) to establish the degree that sequences overlapped between organ injuries (low overlap as key to diagnostic specificity).
