The scale bar represents the estimated number of nucleotide substitutions per nucleotide site.
Differences among nucleotide sequences were due to insertions/deletions of 1- 6 nucleotides and substitution events.
Given the similarity of the sequences analysed, the nucleotide alignments are obvious and are not shown here.
The nucleotide binding site is located in a pocket between the two domains.
A protein's selectivity for a particular nucleotide, for example, is quantified in terms of its relative affinities for two different, but similar, nucleotides.
The nucleotides and amino acids are numbered along the upper and lower of the margins, respectively.
The enzyme was purified and its ability to be activated by cyclic nucleotides was examined.
Consistent with the observation that -butyrolactone receptors recognize the same nucleotide sequence, the residues on helix 3 are completely conserved among the receptors.