This within-host competition for recognition sequences may have driven the evolution of the individual specificity and the collective diversity in target sequence recognition by restriction modification systems.
Most of these approaches attack the difficult problem of what to do when relatively little is known about the regulatory system and sequence recognition by the protein.
Although this general rule regarding specificity holds true, it is an over-simplification, and the sequence recognition specificity of the CRISPR system is a topic of active investigation (Cho et al., 2014; Esvelt et al., 2013; Pattanayak et al., 2013; Ran et al., 2013b; Ren et al., 2013).
In the standard CRISPR-Cas9 system, the reduced sequence recognition stringency that is observed might come from the evolutionary advantage of an adaptive acquired immune system: a less stringent Cas9 endonuclease that tolerates some mismatches between the crRNA and an evolving invading genome may have been selectively preserved through evolution (Carroll, 2013).
In the specificity subunit of Type I restriction-modification systems, DNA sequence recognition is mediated by target recognition domain 1 (TRD1) and TRD2.
If active, the above deletion mechanism through repeat-mediated recombination represents a novel route for the variation of sequence recognition by Type I RM systems.
A Kinect sensor was used to collect image sequences of the operators, and the recognition system relied on the "player extraction" function of the Kinect sensor.
Furthermore, as both systems use very different initial mechanisms of DNA sequence recognition, it is possible that in some cases where one system fails or is inefficient, the other might work better (Hwang et al. 2013; Auer et al. 2014).
Regarding the TpA avoidance observed in vertebrate-infecting viruses, a TpA recognition system in viral RNA sequences is described as a vertebrate immune response mechanism.
Thus there are various applications of HMMs in different research areas such as in diverse sequence recognition tasks [13], in the design of automatic speech recognition systems [18, 35], in natural language processing [36], in online character recognition of handwriting [13] and signature verification [37], in bioinformatics [38], as well as in automatic translation tasks [39].
