Question

The protein Xpot transports tRNAs out of the nucleus so that they can be aminoacylated in the cytosol.

(a) What tRNA structural features is Xpnt likely to recognize?

(b) How does Xpot distinguish mature tRNAs from pre-tRNAs?

Short answer

(a). Xpot must recognize all of the structures of the tRNA to properly start translocation.

(b) Xpot can distinguish mature tRNAs because they have a phosphate group on the 5’ end and a -CCA sequence on the 3’ end. The pre-tRNA still has a leader sequence on the 5’ end and nucleotides other than -CCA on the 3’ end.

Step-by-step solution

Definition of Concept

The transfer ribonucleic acid (tRNA) is a type of RNA that aids in the translation of a messenger RNA (mRNA) sequence to produce a protein.

tRNA structural features that Xpnt is likely to recognize

(a) In order to start translocation properly, Xpot must recognize all of the tRNA structures. It includes the loops of tRNA and the acceptor stem.

Xpot distinguish mature tRNAs from pre-tRNAs

(b) Xpot can detect mature tRNAs because they feature a phosphate group on the 5’ end and a -CCA sequence on the 3’ end. In contrast, there is still a leader sequence on the 5’ end, and there are nucleotides other than -CCA on the 3’ end in the pre-tRNAs.