Ribonuclease 4, an evolutionarily highly conserved member of the superfamily.
The structural and enzymatic properties of RNase 4 are reviewed. This RNase shows a much higher interspecies similarity (approximately 90%) than the other members of the RNase A superfamily. The enzyme is ubiquitous, with the highest amounts present in liver and lung. Its unique uridine specificity results from alterations in and around the pyrimidine-binding site. In particular, the shortened C-terminus and the side chains of Phe-42, Asp-80 and Arg-101 appear to be involved. RNase 4 binds tightly to the intracellular RNase inhibitor, with a Kd of 4 x 10(-15) M.
Friedrich Miescher Institute, Basel, Switzerland.
J
J
Hofsteenge
A
A
Vicentini
O
O
Zelenko
D000595:Amino Acid Sequence; D000818:Animals; D017124:Conserved Sequence; D019143:Evolution, Molecular; D006801:Humans; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics*; D012260:Ribonucleases / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
D012260:Ribonucleases; C083939:ribonuclease 4