XVI
Contents
Glycosylases
556
Alterations of DNA Molecules
557
General Mechanisms for Repair
of DNA
557
Photoreactivation
557
Excision Repair
557
Recombination Repair
558
SOS Repair
559
Human Diseases and DNA Repair
Deficiency
559
24.6
DNA Mutation
559
Types of Mutations
559
Triplet Repeats and Fragile Sites
560
Supplemental Readings
and References
562
CHAPTER
25
RNA and Protein Synthesis
25.1
Structure of RNA
564
Ribosomal RNA (rRNA)
564
Transfer RNA (tRNA)
564
25.2
Messenger RNA
564
25.3
Enzymatic Synthesis of RNA
566
25.4
Prokaryotic Transcription
566
Lifetime of Prokaryotic mRNA
568
25.5
Transcription in Eukaryotes
568
Eukaryotic RNA Polymerases
568
RNA Polymerase II Promoters
569
RNA Polymerase III Promoters
569
Eukaryotic mRNA Synthesis
569
Capping and Polyadenylylation
569
Splicing of RNA in Eukaryotes
570
Splicing and Ribozymes
571
25.6
Genetic Code
571
“Universal” Genetic Code
571
Genetic Code of Mitochondria
572
25.7
Attachment of Amino Acid to tRNA
Molecule
574
25.8
Initiator tRNA Molecules and Selection of
Initiation Codon
574
25.9
Ribosomes
575
Chemical Composition of Prokaryotic
Ribosomes
575
Ribosomes Are Ribozymes
575
Chemical Composition of Eukaryotic
Ribosomes
576
25.10 Protein Synthesis
576
Stages of Protein Synthesis
576
Role of GTP
579
Posttranslational Modification of
Proteins
579
Coupled Transcription and
Translation
580
Endoplasmic Reticulum
580
Compartment Disorders
581
Inhibitors of Protein Synthesis and Related
Disorders
584
25.11 Collagen Biosynthesis and Its
Disorders
585
Transcription and Translation of Collagen
Polypeptides
586
Intracellular Posttranslational
Modifications
587
Hydroxylations of Selected Prolyl and
Lysyl Residues
587
Glycosylation of Hydroxylysyl
Residues
588
Formation of Disulfide Linkages and Assembly of
Procollagen Polypeptides into a Triple Helix
588
Translocation and Secretion of
Procollagen
589
Extracellular Posttranslational
Modification
589
Formation of Collagen Fibrils from Ordered
Aggregation of Collagen Molecules
589
Supplemental Readings
and References
590
