Sandbox Reserved 192: Difference between revisions

RNase A was believed to originate 35 million years ago from bovids [http://en.wikipedia.org/wiki/Bovid] (Opitz et al. 1997). However, RNase A has undergone duplication six times since amphibians and mammals diverged, giving rise to RNase variants in homologues. RNase A homologues have been found in frogs and humans by comparing the amino acid sequences of these particular enzymes with RNase A and seeing what residues were conserved. <scene name='Sandbox_Reserved_192/Conserved_residues/2'>Conservation of amino acid residues</scene>, shown here for the homologues of RNase A, can either support or refute theories of protein structure and function. There have been over 40 different RNase homologues that have been sequenced. Conservation of amino acids Lys41 and His12 and His119 maintain the catalytic function within RNase A homologues.  However, these RNase A homologues differ in cytotoxicity and also have slight differences in sequences which may lead to different particular functions. One homologue, angiogenin, promotes neovascularization [http://en.wikipedia.org/wiki/Neovascularization]. Unusual homologues include other RNase homologues in the human body such as in urine and red blood cells. (Raines)