Question

The enzyme that catalyzes the initial processing of miRNAs in the nucleus is:

A. Drosha.
B. Dicer.
C. Argonaute.
D. RNase A.

Answer 1

Drosha is the enzyme that catalyzes the initial processing of miRNAs in the nucleus.

Step-by-step explanation:

The enzyme that catalyzes the initial processing of miRNAs in the nucleus is Drosha. MiRNAs are small (~23 nt) RNA molecules that control gene expression at the post-transcriptional level. They are synthesized from hairpin precursors and processed by two duplex-specific endonucleases, Drosha and Dicer. Drosha catalyzes the cleavage of the primary miRNA transcript, while Dicer is responsible for the production of mature miRNAs.