Although the lyase domain of members of the LanL and RamC families does not display obvious sequence similarity with that of members of the two other lantipeptide dehydratase families (LanB and LanM), close examination of multiple-sequence alignments exhibits two weakly homologous regions.
One wonders whether Theobald should have perhaps commented on the "razor sharp" intellectual insight of those 2000 and 2001 authors to infer that the proteins that they identified are related via common ancestry (because of obvious sequence similarity), the conclusion in the title of Theobald's paper.
In addition, the contigs in the assembled C. hominis and C. muris termini of chromosome 2 show no regions of obvious sequence similarity to the Cops-1 gene.
It is plausible, therefore, that relative specificity functions as a conserved mechanism even in the absence of obvious sequence homology.
Despite the lack of obvious sequence similarity, several conserved properties between PRC1 and the putative SOP-2/SOR-1 complex suggested a conservation of the mechanism [ 27, 28].
Even though Mde4 and Lrs4 do not share any obvious sequence identity, several lines of evidence are consistent with the notion that Mde4 is the fission yeast counterpart of Lrs4.
Even in the absence of obvious sequence similarity, structural similarity between two protein structures can imply common ancestry, which in turn can suggest a similar function (i.e. a binding site).
Attempts to model TOR to related PI3Ks, either for insights in drug design or for insights on regulation and function of TOR, have been hampered by the fact that the regions of obvious sequence similarity between TOR and PI3Ks are too limited for automated alignment programs used by computational biologists.
However, there is no obvious sequence similarity between the most of internal regions of CMITE family I and AmiPB1.
However, upon visual inspection of sequence alignment, we found obvious sequence similarity to the C2 domain of human PTEN protein, including the regions that make PTEN Ca2+ independent (Fig. 4).
