Type IV Ifs consist of the three related subunits

NF-L, NF-M, and NF-H that make up the neurofilaments found in the axons of neurons

TLS Online TPP Program

#Id: 6700

#Unit 3. Fundamental Processes

The introns in pre-tRNA vary in length from 14 to 60 bases and only single intron is found in each pre-tRNA transcript A pre-tRNA intron is excised in one step  Finally, hydrolysis of GTP and ATP is required to join the two tRNA halves generated by cleavage on either side of the intron.

TLS Online TPP Program

#Id: 6701

#Unit 3. Fundamental Processes

TLS Online TPP Program

#Id: 6702

#Unit 3. Fundamental Processes

Single intron that is located just one nucleotide beyond the 3’ side of the anticodon

TLS Online TPP Program

#Id: 6703

#Unit 3. Fundamental Processes

Splicing of pre-tRNAs is catalyzed by proteins, not by RNAs. The box H/ACA snoRNPs are involved in pseudouridylylation, and box C/D snoRNPs function in 2-O-methylations

TLS Online TPP Program

#Id: 6704

#Unit 3. Fundamental Processes

The mechanism of pre-tRNA splicing differs in three fundamental ways from the mechanisms used by self-splicing introns and spliceosomes.

First, splicing of pre-tRNAs is catalyzed by proteins, not by RNAs. Second, a pre-tRNA intron is excised in one step thatentails simultaneous cleavage at both ends of the intron. Finally, hydrolysis of GTP and ATP is required to join the two tRNA halves generated by cleavage on either side of the intron.

TLS Online TPP Program

#Id: 6705

#Unit 3. Fundamental Processes

The snoRNAs are 60 to 300 nucleotides long. Many are encoded within the introns of other genes and cotranscribed with those genes. Each snoRNA includes a 10 to 21 nucleotide sequence that is perfectly complementary to some site on an rRNA.