1 Protein Synthesis and Translation Inhibitors.- 1 Introduction.- 2 Site of Action of Protein Synthesis Inhibitors.- 3 Selective Action of Translation Inhibitors.- 4 Translation of mRNA.- 2 Initiation.- 1 Introduction.- 2 Inhibitors of Recognition of the Initiator Substrate [Step (a)].- 2.1 Kasugamycin.- 2.2 Showdomycin.- 2.3 Hemin-Controlled Repressor (Translational Inhibitor) and cAMP.- 2.4 Double-Stranded RNA and Interferon.- 3 Inhibitors of Initiator and mRNA Recognition [Steps (a) and (b)].- 3.1 Aurintricarboxylic Acid and Other Triphenyl methane Dyes.- 3.2 Adrenochrome, Polydextran Sulphate, and Polyvinyl Sulphate.- 4 Inhibitors of mRNA Recognition [Step (b)].- 4.1 Edeine A1.- 4.2 7-Methylguanosine-5? Monophosphate.- 5 Inhibitors of Subunit Joining [Step (c1)].- 5.1 Fluoride Salts.- 5.2 MDMP (2 - (4-methyl-2,6-dinitroanilino)-N-methyl-propionamide).- 6 Inhibitors of the Positioning of the Initiator in the Donor Site [Step (c2)].- 6.1 Pactamycin.- 7 Unclassified Inhibitors of Initiation.- 7.1 Streptomycin and Related Aminoglycoside Antibiotics.- 7.2 Pleuromutilin and Related Compounds.- 7.3 5-Azacytidine.- 7.4 Thermorubin.- 7.5 Inhibition of Translation After Viral Infection.- 7.6 Inhibition of Protein Synthesis by Compounds Affecting the Function of the Plasma Membrane.- 7.7 Hypertonic Media.- 7.8 Temperature Shift-down.- 7.9 3-Methyleneoxindole.- 7.10 Cl-Ions.- 7.11 Nitrofurans (Nitrofurantoin).- 7.12 2? (3?), 5? - ADP.- 7.13 Other Antibiotics and Compounds Proposed as Inhibitors of Initiation.- 3 Elongation.- 1 Introduction.- 2 Compounds Interfering with Aminoacyl -tRNA Recognition [Step (d)].- 2.1 Inhibitors of Aminoacyl -tRNA Binding.- 2.1.1 The Tetracycline Antibiotics.- 2.1.2 Antibiotics of the Thiostrepton Group and Multhiomycin (Nosiheptide).- 2.1.3 Micrococcins and Thiocillins.- 2.1.4 Fusidic Acid.- 2.1.5 Ricin and Abrin.- 2.1.6 PAP, Alpha Sarcin, Restrictocin, Mitogillin, Crotins, Curcins, Enomycin, Phenomycin, and Modeccin.- 2.1.7 Chartreusin.- 2.1.lc1