Catalytic complexes of nuclear ribonuclease P (RNase P)
ribonucleoproteins are composed of several protein subunits
that appear to have specific roles in enzyme function in tRNA
processing. This review describes recent progress made in the
characterization of human RNase P, its relationship with the
ribosomal RNA processing ribonucleoprotein RNase MRP, and the
unexpected evolutionary conservation of its subunits. A new
model for the biosynthesis of human RNase P is presented, in
which this process is dynamic, transcription-dependent, and
implicates functionally distinct nuclear compartments in tRNA
biogenesis.