Dear Wei, The enzyme ribonucleotide reductase can, depending on organism and class, bind ATP as a substrate in the active site (c), as an allosteric regulator of substrate specificity at another site (s) and as an overall activity regulator at a third site (a)! It can also bind dATP at the second and third sites, but not as a substrate. It cannot bind to sites (c) and (s) at the same time although it could potentially bind to sites (s) and (a) simultaneously. Here is a review that you might find useful:
http://www.ncbi.nlm.nih.gov/pubmed/22050358 Best wishes Derek On 4 Mar 2014, at 04:48, Wei Shi <[email protected]> wrote: > Dear all, > Does anyone happen to know examples of 2 ligands bind to a single protein / > each monomer protein in 2 different ligand binding pockets? > I know the following example: > (1). phosphofructokinase, which binds ATP as both a ligand and a feedback > inhibitor in different sites > (2). 2 cAMP bound to each E. coli CAP monomer in the crystal structure. > > Does any of you know other examples? Thank you so much! > > Best, > Wei
