Protamine biosynthesis

Polysaccharides, 44, 58 Prokaryote Cell, 7 Proline, 439 Promoters, 391 Protamines, 149 Proteans, 151 Protein Biosynthesis, 448 Protein Catabolism, 428 Protein Maturation, 449 Proteins, 262 Purine Metabolism, 379 Purines, 113 Pyridoxine, 229 Pyrimidines, 113 Pyruvate Kinase, 288... 

Ling, V., J. R. Trevithick, and G. H. Dixon. 1969. The biosynthesis of protamine in trout testis. I. Intracellular site of synthesis. Canad. J. Biochem., 47 51-60. 

Nucleoprotein heteropolar complexes of nucleic acids (in particular, nuclear DNA) with basic, acid-soluble proteins (histones or protamines), and with acidic, base- or detergent-soluble non-histone chromatin proteins. N. occur mainly in the chromatin of the cell nucleus in its quiescent state, and in the chromosomes when the nucleus is active, i.e. dividing. Many viruses consist entirely of N., but N. are absent from bacteria. N. are concerned in DNA replication, and in the control of gene function during protein biosynthesis. 

Whether the interaction between histone and DNA is specific and occurs in vivo to repress DNA is not certain. However, it cannot be excluded that the histones interfere with the polymerase reaction simply by making the primer unavailable in a fashion common to all basic polymers. Histones and protamines interfere with the hydrolysis of DNA by deoxyribonuclease, and it thus can be established that the interference results from the precipitation of substrate. Injected, histones have been claimed to interfere with DNA biosynthesis in regenerating liver. Such intriguing observations undoubtedly have to be confirmed in several laboratories before their full impact can be appreciated. In conclusion, modern studies suggest that histones may be important in the transfer of genetic information from DNA to messenger RNA, but the molecular details remain to be elucidated. 

Histones and protamines are present in animal cell nuclei as basic nuclear proteins associated with deoxyribonucleic acid. They are known to be inhomogeneous and probably consist of definite amounts of several components which are very similar in their nature and structure. The significance of the heterogeneity of these basic nuclear proteins has not yet been completely elucidated, though some particular activity in controlling DNA-dependent biosynthesis is sometimes attributed to each component of the histones. 

Ingles, C. J., Trevithick, J. R., Smith, M., Dixon, G. H. Biosynthesis of protamine during spermatogenesis in salmonoid fish. Biochem. biophys. Res. Commun. 22, 627—634 (1966). 

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