DNA-Dependent
Synthesis of RNA
RNA Is
Synthesized by RNA Polymerases
RNA
Synthesis Is Initiated at Promoters
BOX 25-1 RNA
Polymerase Leaves Its FootPrint on a Promoter
Initiation
of Transcription Is Regulated
Eukaryotic
Cells Have Three Kinds of RNA Polymerases
Specific
Sequences Signal Termination of RNA Synthesis
DNA-Directed
RNA Polymerase Can Be Selectively Inhibited
RNA Processing
The
Introns Transcribed into RNA Are Removed by
Splicing
Eukaryotic
mRNAs Undergo Additional Processing
Multiple
Products Are Derived from One Gene by
Differential RNA Processing
Ribosomal
RNAs and tRNAs Also Undergo Processing
Some
Events in RNA Metabolism Are Catalyzed by RNA
Enzymes
Cellular
mRNAs Are Degraded at Different Rates
Polynucleotide
Phosphorylase Makes Random RNA-like Polymers
RNA-Dependent
Synthesis of RNA and DNA
Reverse
Tanscriptase Produces DNA from Viral RNA
Some
Retroviruses Cause Cancer or AIDS
BOX 25-2 Fighting
AIDS with Inhibitors of HIV Reverse Transcriptase
Many
Eukaryotic Transposons Are Related to
ftetroviruses
Telomerase
Is an Enzyme Resembling Reverse Transcriptase
Some
Viral RNAs Are Replicated by RNA-Directed RNA
Polymerase
RNA
Synthesis Offers Important Clues to Biochemical
Evolution
Summary
Further Reading
Problems
